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ISSN: 2056-9890
Volume 71| Part 10| October 2015| Pages 1125-1131

Crystal structures of 1-bromo-3,5-bis­­(4,4-di­methyl-1,3-oxazolin-2-yl)benzene 0.15-hydrate and 3,5-bis­­(4,4-di­methyl-1,3-oxazolin-2-yl)-1-iodo­benzene

CROSSMARK_Color_square_no_text.svg

aInstitute of Inorganic and Applied Chemistry, Department of Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, D-20146 Hamburg, Germany
*Correspondence e-mail: michael.froeba@chemie.uni-hamburg.de

Edited by A. J. Lough, University of Toronto, Canada (Received 12 August 2015; accepted 27 August 2015; online 12 September 2015)

The bromo and iodo derivatives of a meta-bis­(1,3-oxazolin-2-yl)-substituted benzene, C16H19BrN2O2·0.15H2O (1) and C16H19IN2O2 (2), have been prepared and studied in terms of their mol­ecular and crystal structures. While the former crystallizes as a sub-hydrate, with 0.15 formula units of water and shows an almost all-planar arrangement of the three ring systems, the latter crystallizes solvate-free with the flanking heterocycles twisted considerably with respect to the central arene. Non-covalent contacts include parallel-displaced ππ inter­actions and (non-classical) hydrogen bonding for both (1) and (2), as well as relatively short I⋯N contacts for (2).

1. Chemical context

The 2-oxazolinyl functional group has been employed as a protective group for carb­oxy­lic acids rendering them stable against organometallic reagents (Wuts & Greene, 2007[Wuts, P. G. W. & Greene, T. W. (2007). Organic Synthesis, 4th ed. New Jersey: Wiley.]). Aromatic 1,3-substituted bis­(1,3-oxazolin-2-yl) compounds have shown to be efficient for directed ortho metallation (DoM) reactions (Harris et al., 1978[Harris, T. D., Neuschwander, B. & Boekelheide, V. (1978). J. Org. Chem. 43, 727-730.]), while competitive halogen–metal exchange reactions should be considered for the halide-substituted title compounds reported herein. The substitutional pattern also gives access to bis­(1,3-oxazolin-2-yl) systems suitable for the preparation of N,C,N-tridentate pincer ligands which have come to general attention as Phebox ligands [Phebox: 2,6-bis­(1,3-oxazolin-2-yl)phen­yl].

There are many examples for respective organometallic complexes of transition and rare-earth metals known in the literature with many of them bearing chiral 2-oxazolinyl substituents within the Phebox ligand. Exemplary compounds include those of some early transition metals (Chuchuryukin et al., 2011[Chuchuryukin, A. V., Huang, R., Lutz, M., Chadwick, J. C., Spek, A. L. & van Koten, G. (2011). Organometallics, 30, 2819-2830.]), iridium (Allen et al., 2014[Allen, K. E., Heinekey, D. M., Goldman, A. S. & Goldberg, K. I. (2014). Organometallics, 33, 1337-1340.]), or palladium (Lu et al., 2010[Lu, Z.-L., Yang, X.-S., Guo, Z.-F. & Wang, R.-Y. (2010). J. Coord. Chem. 63, 2659-2672.]), to name but a few.

The substitution with bromine and iodine renders the title compounds capable of being utilized as potential precursors for C–C cross-coupling building blocks bearing the Phebox motif.

[Scheme 1]

2. Structural commentary

The structural considerations below take least-squares mean planes for rings A (O1/C7/N1/C9/C8) and C (O2/C12/N2/C14/C13) of the heterocyclic 2-oxazolinyl groups and B (C1/C2/C3/C4/C5/C6) for the central arene into account. For both (1) and (2), the 2-oxazoline moiety with an approximately accordant orientation of the C=N bond with respect to the C5—X1 (X = Br, I) bond was chosen to be denoted as ring A.

Compound (1) crystallized from water-containing aceto­nitrile as an adduct with 0.15 H2O in the monoclinic space group P21/n. Within the mol­ecular structure (Fig. 1[link]) the 2-oxazolinyl functional groups are oriented anti­periplanar to each other. The elongated displacement ellipsoid of the methyl­ene carbon atom C13 indicates a noteworthy vibrational freedom orthogonal to plane C which was not observed for atoms within ring A. The absence of a comparable displacement component of C14 perpendicular to plane C disagrees with pseudorotational disorder around the atomic positions mentioned.

[Figure 1]
Figure 1
The asymmetric unit of (1), shown with 50% probability displacement ellipsoids. H atoms are drawn as green spheres of an arbitrary radius.

The five-membered heterocyclic moieties possess different conformational characteristics. Within ring A, significant puckering with parameters τm = 13.2 (1)°, q2 = 0.1284 (19) Å, and φ2 = 134.2 (9)° indicate a C8TC9 conformation distorted towards C8E (Altona & Sundaralingam, 1972[Altona, C. & Sundaralingam, M. (1972). J. Am. Chem. Soc. 94, 8205-8212.]; Cremer & Pople, 1975[Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354-1358.]). Ring C shows only slight deviation from ideal planarity with τm = 3.5 (1)°.

Inter­planar angles of 2.15 (12)° and 3.67 (16)° of the planes N1/C7/O1 and N2/C12/O2 with plane B, respectively, have been found for the almost all-planar overall structure. Considerable angular deviations from ideal (120°) angles within ring B were found for C4—C5—C6 = 122.04 (15)°, C3—C4—C5 = 118.75 (15), and C1—C6—C5 = 118.59 (14)°.

The water mol­ecule is involved in hydrogen bonds with N1⋯H3A = 1.96 (2) Å and O3⋯H6 = 2.548 (9) Å, where the corresponding angles are O3—H3A⋯N1 = 178 (15)° and C6—H6⋯O3 = 148.6 (3)°, respectively. Hydrogen-bond geometries for (1) are summarized in Table 1[link].

Table 1
Hydrogen-bond geometry (Å, °) for (1)[link]

D—H⋯A D—H H⋯A DA D—H⋯A
C6—H6⋯O3 0.95 2.55 (1) 3.395 (10) 149 (1)
O3—H3A⋯N1 0.84 (2) 1.96 (2) 2.796 (10) 178 (15)
C16—H16B⋯O3i 0.98 2.18 (1) 3.045 (11) 146 (1)
C13—H13B⋯O3i 0.99 2.94 (1) 3.656 (12) 130 (1)
C8—H8B⋯Br1ii 0.99 3.09 (1) 4.054 (2) 165 (1)
C11—H11C⋯O3iii 0.98 2.56 (1) 3.391 (12) 143 (1)
O3—H3B⋯N1iii 0.84 (2) 2.37 (9) 3.107 (11) 148 (15)
O3—H3B⋯O3iii 0.84 (2) 2.32 (13) 2.90 (2) 126 (13)
Symmetry codes: (i) [-x+{\script{1\over 2}}, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]; (ii) x-1, y, z; (iii) -x, -y+1, -z.

The isostructural iodo derivative (2) was crystallized from di­chloro­methane with no evidence of co-crystallized solvent. Again, an anti­periplanar orientation of the 2-oxazolinyl moieties within the mol­ecular structure (Fig. 2[link]) was found. In contrast to (1), a more distinct twisting of the planes N1/C7/O1 and N2/C12/O2 compared to the plane B with inter­planar angles of 16.16 (4) and 15.14 (4)°, respectively, was found.

[Figure 2]
Figure 2
The asymmetric unit of (2), shown with displacement ellipsoids drawn at the 50% probability level. H atoms are drawn as green spheres of arbitrary radius.

For (2), similar conformational considerations as for (1) apply. Puckering parameters τm = 19.6 (1)°, q2 = 0.1902 (11) Å, and φ2 = 135.5 (3)° indicate a conformation between C8TC9 and C8E for ring C. A higher degree of planarity was found for ring A with τm = 4.6 (1)°. The bond length C5—I1 is 2.0968 (9) Å with I1 located 0.1183 (14) Å above ring B and thus considerably more distant than the bromine atom in (1), where Br1 lies only 0.005 (2) Å above plane B. The deviation occurs away from a ππ stacked (see also below) inversion-equivalent formula unit and might be the consequence of steric repulsion between the bulky iodine substituent and the 2-oxazolinyl groups of the neighboring formula unit. Noteworthy deviations from ideal angles within ring B were found with C4—C5—C6 = 121.35 (9)° and C3—C4—C5 = 118.60 (9)°. I1 shows an angular adjustment to C6—C5—I1 = 117.08 (7)°, thus improving inter­molecular N⋯I contacts (see below).

All bond lengths for (1) and (2) fall within expected ranges (Allen et al., 1987[Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1-S19.]).

3. Supra­molecular features

Within the crystal structure of (1) (Fig. 3[link]), inter­molecular bonding is established by classical and non-classical hydrogen bonding (see Table 1[link]) as well as ππ inter­actions. Close contacts O3⋯H16Bi = 2.181 (10) Å with C16i—H16Bi⋯O3 = 146.2 (3)° and H13B⋯O3i = 2.936 (11) Å with C13—H13B⋯O3i = 130.4 (3)° were found. Further hydrogen-bonding inter­actions arise from mutual inter­actions of two inversion-related water mol­ecules with H3B⋯O3iii = 2.32 (13) Å and O3—H3B⋯O3iii = 126 (13)°.

[Figure 3]
Figure 3
View along the a axis of the crystal packing of compound (1).

Additionally, parallel-displaced ππ stacking with Cg1⋯Cg1i = 3.5064 (12) Å (Cg1 denotes the centroid calculated for the arene atoms) and a horizontal displacement of I = 0.996 (2) Å (for a description of geometric parameters of ππ associated arenes, see: Snyder et al., 2012[Snyder, S. E., Huang, B.-S., Chu, Y. W., Lin, H.-S. & Carey, J. R. (2012). Chem. Eur. J. 18, 12663-12671.]) between the centroids was found. The inter­planar distance is R = 3.3620 (13) Å. The ππ inter­action gives rise to anti­periplanar dimers linked to each other by an inversion. Features of inter­molecular bonding for (1) are illustrated in Fig. 4[link].

[Figure 4]
Figure 4
Inter­molecular contacts within the crystal structure of (1) are established by means of parallel-displaced ππ inter­actions and hydrogen bonding. Displacement ellipsoids are at the 50% probability level and inter­molecular contacts are depicted as dashed lines. Only H atoms involved in hydrogen bonding or van der Waals contacts (black dashed lines) are shown as green spheres at an arbitrary radius. Purple dashed lines indicate centroid–centroid connecting lines. [Symmetry codes: (i) −x + 1, −y + 1, −z + 1; (ii) −x + [{1\over 2}], y + [{1\over 2}], −z + [{1\over 2}]; (iii) x − [{1\over 2}], −y + [{3\over 2}], z − [{1\over 2}].]

The supra­molecular contacts found for (2) are depicted in Fig. 5[link]. A comparable ππ stacking motif as for compound (1) was found within the crystal structure of (2) (Fig. 6[link]). The centroid–centroid distance Cg1⋯Cg1i = 3.6142 (8) Å is slightly increased compared to (1). The inter­planar distance is R = 3.2862 (9) Å with a remarkably increased horizontal centroid–centroid displacement of I = 1.5044 (15) Å.

[Figure 5]
Figure 5
Supra­molecular features within the crystal structure of (2) comprise ππ contacts and mutual N1⋯I1ii and N1ii⋯I1 inter­actions. Moreover, there are non-conventional hydrogen bonds I1ii⋯H6, I1⋯H6ii, and H10B⋯N2iii. Inter­molecular contacts are shown as dashed lines. Only atoms H6, H6ii, and H10B which are involved in hydrogen bonding (black dashed lines) are shown as green spheres of an arbitrary radius. Purple dashed lines connect centroids of ππ associated dimers. [Symmetry codes: (i) −x + 1, −y + 1, −z + 1; (ii) −x + 1, −y + 2, −z + 1; (iii) −x + [{3\over 2}], y + [{1\over 2}], −z + [{1\over 2}].]
[Figure 6]
Figure 6
View along the a axis of the crystal packing of compound (2).

Mutual hydrogen bonds I1⋯H6ii = I1ii⋯H6 = 3.11 Å with C6—H6⋯I1ii = C6ii—H6ii⋯I1 = 150° and H10B⋯N2ii = 2.745 Å with an angle of C10—H10B⋯N2ii = 172° establish inter­molecular bonding (Table 2[link]). Additionally, particularly short mutual N1⋯I1ii and N1ii⋯I1 contacts at 3.2779 (9) Å were found. The N⋯I distance corresponds to 89% of the sum of the van der Waals radii (3.70 Å; Alvarez, 2013[Alvarez, S. (2013). Dalton Trans. 42, 8617-8636.]) of the atoms involved. To the best of our knowledge, the shortest N⋯I contact found in a crystal structure was recently reported to be 2.622 Å (Bosch, 2014[Bosch, E. (2014). Cryst. Growth Des. 14, 126-130.]), corresponding to 71% of the sum of the van der Waals radii. With respect to I1⋯N1ii contacts, the angle C5—I1⋯N1ii = 155.61 (3)° is found to be slightly linearized by an angular adaption C6—C5—I1 (see above).

Table 2
Hydrogen-bond geometry (Å, °) for (2)[link]

D—H⋯A D—H H⋯A DA D—H⋯A
C6—H6⋯I1i 0.95 3.11 3.9679 (9) 150
C10—H10B⋯N2ii 0.98 2.75 3.7228 (15) 172
Symmetry codes: (i) -x+1, -y+2, -z+1; (ii) [-x+{\script{3\over 2}}, y+{\script{1\over 2}}, -z+{\script{1\over 2}}].

The halogen-halogen distances for (1) and (2) exceed the sum of the van der Waals radii and lack appropriate angles for halogen–halogen bonding.

4. Database survey

The crystal structure of the reagent used to prepare compounds (1) and (2) (see also below), 5-bromo-1,3-di­cyano­benzene, has been published recently (CCDC reference number DIRLEX; Seidel et al., 2013[Seidel, N., Seichter, W. & Weber, E. (2013). Acta Cryst. E69, o1732-o1733.]).

A WebCSD search (Version 1.1.1, updated July 2015; Groom & Allen, 2014[Groom, C. R. & Allen, F. H. (2014). Angew. Chem. Int. Ed. 53, 662-671.]) for the 1,3-bis­(1,3-oxazolin-2-yl)benzene substructure gave 143 hits. Very few of the crystal structures show the parent motif without any metal ion bound to it. The following considerations take into account only purely organic structures with a 1,3-substitutional pattern, although a significant number of (metal coordinated) 1,3,5-tri(1,3-oxazolin-2-yl)benzenes has been reported.

1-Iodo-2,6-bis­(4′-isopropyl-1,3-oxazolin-2-yl)-4-tert-butylbenzene (ROHMIL; Bugarin & Connell, 2008[Bugarin, A. & Connell, B. T. (2008). Organometallics, 27, 4357-4369.]) and 1,3-bis­(4,4-dimethyl-1,3-oxazolin-2-yl)-2-(tri­methyl­stann­yl)benzene (FILNAQ; Stol et al., 2005[Stol, M., Snelders, D. J. M., de Pater, J. J. M., van Klink, G. P. M., Kooijman, H., Spek, A. L. & van Koten, G. (2005). Organometallics, 24, 743-749.]) show substitutional variation from compounds (1) and (2). By introducing sterically demanding substituents ortho to the 1,3-oxazolin-2-yl groups, these are considerably more twisted against the parent arene ring plane with twisting angles ranging from 47.3 (2)–63.6 (2)° and 22.35 (8)–22.75 (8)° for the iodo and tin derivatives, respectively. The more distinct twisting of the respective groups in (2) with 16.16 (4) and 15.14 (4)° compared to (1) [2.15 (12) and 3.67 (16)°] might be attributed to geometrical requirements for the formation of supra­molecular bonding observed for (2). 1-Iodo-2,6-bis­(4′-isopropyl-1,3-oxazolin-2-yl)-4-tert-butyl­benzene shows short N⋯I distances at 3.041 (6) Å corresponding to 82% of the sum of van der Waals radii.

Other structures generally lack halide substitution at the central arene, although substitutional variety at the 4′-positions was found. Instead of 4,4-dimethyl substitution, derivatives bearing hydrogen atoms (LAFNEM; Chen et al., 2004[Chen, S.-H., Li, S.-F., Zou, Y., Yang, L., Chen, B. & Zhu, H.-L. (2004). Z. Kristallogr. New Cryst. Struct. 219, 153-154.]), hy­droxy­methyl (MODQIH; Javadi et al., 2014[Javadi, M. M., Moghadam, M., Mohammadpoor-Baltork, I., Tangestaninejad, S., Mirkhani, V., Kargar, H. & Tahir, M. N. (2014). Polyhedron, 72, 19-26.]) or isopropyl groups (DOWGOM; Mei et al., 2009[Mei, L., Hai, Z. J., Jie, S., Ming, Z. S., Hao, Y. & Liang, H. K. (2009). J. Comb. Chem. 11, 220-227.]) have been found. For those structures, no features of inter­molecular ππ inter­actions could be observed. Instead, C—H⋯π inter­action becomes obvious for LAFNEM and DOWGOM. It is supposed that halide substitution increases dispersion inter­action at modest horizontal centroid-centroid separations (Arnstein & Sherrill, 2008[Arnstein, S. A. & Sherrill, C. D. (2008). Phys. Chem. Chem. Phys. 10, 2581-2583.]), thus promoting ππ stacking for (1) and (2). As a result of the presence of electronegative atoms, hydrogen bonding and van der Waals contacts can also be found for the structures mentioned.

Structures DOWGOM, FILNAQ, MODQIH, and ROHMIL show a synperiplanar orientation of the 2-oxazolinyl groups. The anti­periplanar arrangement as in (1) and (2) was only found for LAFNEM.

Langer et al. found the same C8TC9 conformation (with respect to the numbering scheme used herein) within the 2-oxazoline ring of 2-(4-hy­droxy­phen­yl)-4,4-dimethyl-2-oxazoline (CELMAI; Langer et al., 2006[Langer, V., Gyepesová, D., Scholtzová, E., Lustoň, J., Kronek, J. & Koóš, M. (2006). Acta Cryst. C62, o416-o418.]) as for the 2-oxazoline moieties in (1) and (2). Conformational analysis of the 2-oxazolines within the structures discussed herein showed that all possible conformations twisted around C8—C9 can be found, that are C8TC9 (two times within DOWGOM, CELMAI) and C9TC8 (LAWCAO, ROHMIL). Folding into an envelope conformation was only observed at C8 with examples for C8E (two times within DOWGOM, ROHMIL) and EC8 (FILNAQ, two times within ROHMIL) conformations. This might suggest that folding happens preferentially at the less-substituted methyl­ene position. Planar conformations have been found for MODQIH, LAFNEM, and FILNAQ.

5. Synthesis and crystallization

(1) and (2) were synthesized starting from 5-bromo-1,3-di­cyano­benzene (Fig. 7[link]). The multi-step preparation of 5-bromo-1,3-di­cyano­benzene starting from isophthalic acid has been described in a patent (Dillard et al., 2010[Dillard, L. W., Yuan, J., Jia, L. & Zheng, Y. (2010). WO Patent No. 021680 A2.]). For the preparation of compound (1), 5-bromo-1,3-di­cyano­benzene was subjected to cyclization at the cyano positions with 2-amino-2-methyl­propan-1-ol under zinc(II) catalysis (Button et al., 2002[Button, K. M., Gossage, R. A. & Phillips, R. K. R. (2002). Synth. Commun. 32, 363-368.]) to give the meta-bis­(1,3-oxazolin-2-yl) arene. The iodo derivative (2) was synthesized from (1) by an aromatic Finkelstein reaction (Klapars & Buchwald, 2002[Klapars, A. & Buchwald, S. L. (2002). J. Am. Chem. Soc. 124, 14844-14845.]). All reactions were carried out under an atmosphere of dry nitro­gen using standard Schlenk techniques.

[Figure 7]
Figure 7
The synthesis scheme of (1) and (2), starting from 1-bromo-3,5-di­cyano­benzene. The numbering scheme for the title compounds is given.

5.1. 1-Bromo-3,5-bis­(4,4-dimethyl-1,3-oxazolin-2-yl)benzene sub-hydrate (1)

Zinc(II) chloride (73 mg, 0.54 mmol, 0.1 eq.) was melted three times in vacuo with help of a heat gun. 5-Bromo-1,3-di­cyano­benzene (1.13 g, 4.65 mmol, 1.0 eq.), 2-amino-2-methyl­propan-1-ol (870 mg, 9.77 mmol, 2.1 eq.) and chloro­benzene (15 mL) were added, the colorless suspension was magnetically stirred and heated to reflux for 48 h where it became a pink-colored solution. After qu­anti­tative conversion of the di­cyano compound was confirmed via TLC, the reaction mixture was cooled to 353 K. Volatiles were removed in vacuo at 353–433 K. After cooling to room temperature, di­chloro­methane (50 mL) and distilled water (50 mL) were added. The organic layer was separated, the aqueous layer extracted with di­chloro­methane (three times with 20 mL each). The combined organic layers were dried over sodium sulfate, filtered, and the solvent was removed from the filtrate under reduced pressure. Column chromatography of the crude product (SiO2; petrol ether/ethyl acetate = 4:1) gave (1) (1.52 g, 4.33 mmol, 93%) as a colorless solid. Crystallization of (1) from a concentrated solution in aceto­nitrile at 277 K gave single crystals suitable for X-ray structural analysis.

1H-NMR (DMSO-d6, 300.21 MHz): δ (p.p.m.) = 8.28 (t, 1H; 4J(H,H) = 1.5 Hz, H2), 8.06 (d, 2H; 4J(H,H) = 1.5 Hz, H4, H6), 4.16 (s, 4H; H8, H13), 1.30 (s, 12H; H10, H11, H15, H16). 13C{1H}-NMR (DMSO-d6, 75.50 MHz): δ (p.p.m.) = 158.7 (C7, C12), 132.5 (C4, C6), 130.1 (C1, C3), 126.0 (C2), 121.9 (C5), 78.9 (C8, C13), 67.7 (C9, C14), 28.1 (C10, C11, C15, C16). ESI–HRMS(+) m/z: calculated for [M+H]+ 351.0703/353.0688, found 351.0707/353.0689 (79Br/81Br).

5.2. 1-Iodo-3,5-bis­(4,4-dimethyl-1,3-oxazolin-2-yl)benzene (2)

A J. Young ampoule was charged with (1) (500 mg, 1.42 mmol, 1.0 eq.), copper(I) iodide (14 mg, 74 µmol, 5 mol%), and sodium iodide (426 mg, 2.84 mmol, 2.0 eq.). The ampoule was put to vacuum und flushed with nitro­gen three times. 1,4-Dioxane (3 mL) and N,N′-di­methyl­ethylenedi­amine (15 µL, 0.14 mmol, 10 mol%) were added. The ampoule was sealed with a Teflon screw valve, the colorless suspension was magnetically stirred and heated to 373 K for 24 h. An intense blue coloring was observed during the reaction course. After cooling to room temperature, ammonia solution (10 mL, 25%), distilled water (20 mL), and di­chloro­methane (30 mL) were added. The organic layer was separated, the aqueous layer extracted with di­chloro­methane (three times with 10 mL each) and the combined organic phases were dried over sodium sulfate. After filtration, di­chloro­methane was removed from the filtrate under reduced pressure. The crude product was purified by means of column chromatography (SiO2; petrol ether/ethyl acetate = 4:1) to give a colorless solid (2) (505 mg, 1.27 mmol, 89%). Crystallization from a concentrated solution of (2) in di­chloro­methane by slow evaporation of the solvent yielded single crystals suitable for X-ray single crystal diffraction.

1H-NMR (DMSO-d6, 300.21 MHz): δ (p.p.m.) = 8.28 (t, 1H; 4J(H,H) = 1.5 Hz, H2), 8.24 (d, 2H; 4J(H,H) = 1.5 Hz, H4, H6), 4.14 (s, 4H; H8, H13), 1.29 (s, 12H; H10, H11, H15, H16). 13C{1H}-NMR (DMSO-d6, 75.50 MHz): δ (p.p.m.) = 158.6 (C7, C12), 138.2 (C1, C3), 132.5 (C4, C6), 129.8 (C2), 126.2 (C1), 78.8 (C8, C13), 67.7 (C9, C14), 28.1 (C10, C11, C15, C16). EI–MS m/z: calcd. for M+. 398.08, found 398.08 (M+.), 383.06 (M+. – CH3.), 368.07 (M+. – 2CH3.).

6. Refinement

Crystal data, data collection, and structure refinement details are summarized in Table 3[link].

Table 3
Experimental details

  (1) (2)
Crystal data
Chemical formula C16H19BrN2O2·0.15H2O C16H19IN2O2
Mr 353.94 398.23
Crystal system, space group Monoclinic, P21/n Monoclinic, P21/n
Temperature (K) 100 100
a, b, c (Å) 10.0661 (1), 16.2960 (2), 11.0400 (1) 9.6195 (2), 9.9759 (2), 17.2951 (4)
β (°) 114.496 (2) 94.648 (1)
V3) 1647.96 (4) 1654.23 (6)
Z 4 4
Radiation type Mo Kα Mo Kα
μ (mm−1) 2.50 1.94
Crystal size (mm) 0.34 × 0.26 × 0.08 0.22 × 0.12 × 0.08
 
Data collection
Diffractometer Agilent SuperNova Dual Source diffractometer with an Atlas detector Bruker SMART APEX CCD area-detector diffractometer
Absorption correction Multi-scan (CrysAlis PRO; Agilent, 2013[Agilent Technologies (2013). CrysAlis PRO. Agilent Technologies, Santa Clara, California, USA.]) Numerical (SADABS; Bruker, 2014[Bruker (2014). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.])
Tmin, Tmax 0.670, 1.000 0.649, 0.747
No. of measured, independent and observed [I > 2σ(I)] reflections 29541, 5438, 4598 45346, 6463, 6035
Rint 0.035 0.019
(sin θ/λ)max−1) 0.735 0.776
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.035, 0.080, 1.05 0.017, 0.043, 1.07
No. of reflections 5438 6463
No. of parameters 209 194
No. of restraints 3 0
H-atom treatment H atoms treated by a mixture of independent and constrained refinement H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.85, −0.74 0.82, −0.62
Computer programs: CrysAlis PRO (Agilent, 2013[Agilent Technologies (2013). CrysAlis PRO. Agilent Technologies, Santa Clara, California, USA.]), APEX2 and SAINT (Bruker, 2014[Bruker (2014). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]), SUPERFLIP (Palatinus & Chapuis, 2007[Palatinus, L. & Chapuis, G. (2007). J. Appl. Cryst. 40, 786-790.]), SHELXL2014 (Sheldrick, 2015[Sheldrick, G. M. (2015). Acta Cryst. C71, 3-8.]), XP in SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]), WinGX (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]), OLEX2 (Dolomanov et al., 2009[Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339-341.]), publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]) and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

Primary atom site locations were assigned with EDMA (Palatinus et al., 2012[Palatinus, L., Prathapa, S. J. & van Smaalen, S. (2012). J. Appl. Cryst. 45, 575-580.]) from electron densities obtained by SUPERFLIP (Palatinus & Chapuis, 2007[Palatinus, L. & Chapuis, G. (2007). J. Appl. Cryst. 40, 786-790.]). The remaining secondary non-carbon atom sites were located from the difference Fourier map. All non-hydrogen atoms were refined with anisotropic displacement parameters.

Full-matrix least-squares refinement on F2 was done with SHELXL2014/7 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]). Carbon-bound hydrogen atoms were positioned geometrically and refined riding on their respective carbon atom. Bond lengths were fixed at 0.95 Å (aromatic H), 0.98 Å (methyl H), and 0.99 Å (methyl­ene H). Uiso(H) was fixed at 1.5 Ueq(O) and Ueq(C) for hydroxyl and methyl hydrogens or 1.2 Ueq(C) for the remaining hydrogens. Methyl hydrogens were fitted to the experimental electron density by allowing them to rotate around the C—C bond with a fixed angle (HFIX 137).

For (1), occupancy refinement of O3 gave an occupancy of 0.15543 (611) which was subsequently fixed at 0.15. The hydrogen atoms H3A and H3B were located with the help of CALC-OH, which is the WinGX (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]) implementation of Nardelli's method (Nardelli, 1999[Nardelli, M. (1999). J. Appl. Cryst. 32, 563-571.]) of OH atom positioning. The coordinates of those hydrogen atoms were refined freely while applying restraints to the overall water geometry (O—H = 0.84 Å and H⋯H = 1.328 Å).

Supporting information


Chemical context top

The 2-oxazolinyl functional group has been employed as a protective group for carb­oxy­lic acids rendering them stable against organometallic reagents (Wuts & Greene, 2007). Aromatic 1,3-substituted bis­(1,3-oxazolin-2-yl) compounds have shown to be efficient for directed ortho metallation (DoM) reactions (Harris et al., 1978), while competitive halogen–metal exchange reactions should be considered for the halide-substituted title compounds reported herein. The substitutional pattern also gives access to bis­(1,3-oxazolin-2-yl) systems suitable for the preparation of N,C,N-tridentate pincer ligands which have come to general attention as Phebox ligands [Phebox: 2,6-bis­(1,3-oxazolin-2-yl)phenyl].

There are many examples for respective organometallic complexes of transition and rare-earth metals known in the literature with many of them bearing chiral 2-oxazolinyl substituents within the Phebox ligand. Exemplary compounds include those of some early transition metals (Chuchuryukin et al., 2011), iridium (Allen et al., 2014), or palladium (Lu et al., 2010), to name but a few.

The substitution with bromine and iodine renders the title compounds capable of being utilized as potential precursors for C–C cross-coupling building blocks bearing the Phebox motif.

Structural commentary top

The structural considerations below take least-squares mean planes for rings A (O1/C7/N1/C9/C8) and C (O2/C12/N2/C14/C13) of the heterocyclic 2-oxazolinyl groups and B (C1/C2/C3/C4/C5/C6) for the central arene into account. For both (1) and (2), the 2-oxazoline moiety with an approximately accordant orientation of the CN bond with respect to the C5—X1 (X = Br, I) bond was chosen to be denoted as ring A.

Compound (1) crystallized from water-containing aceto­nitrile as an adduct with 0.15 H2O in the monoclinic space group P21/n. Within the molecular structure (Fig. 1) the 2-oxazolinyl functional groups are oriented anti­periplanar to each other. The elongated displacement ellipsoid of the methyl­ene carbon atom C13 indicates a noteworthy vibrational freedom orthogonal to plane C which was not observed for atoms within ring A. The absence of a comparable displacement component of C14 perpendicular to plane C disagrees with pseudorotational disorder around the atomic positions mentioned.

The five-membered heterocyclic moieties possess different conformational characteristics. Within ring A, significant puckering with parameters τm = 13.2 (1)°, q2 = 0.1284 (19) Å, and φ2 = 134.2 (9)° indicate a C8TC9 conformation distorted towards C8E (Altona & Sundaralingam, 1972; Cremer & Pople, 1975). Ring C shows only slight deviation from ideal planarity with τm = 3.5 (1)°.

Inter­planar angles of 2.15 (12)° and 3.67 (16)° of the planes N1/C7/O1 and N2/C12/O2 with plane B, respectively, have been found for the almost all-planar overall structure. Considerable angular deviations from ideal angles within ring B were found for C4—C5—C6 = 122.04 (15)°, C3—C4—C5 = 118.75 (15), and C1—C6—C5 = 118.59 (14)°.

The water molecule is involved in hydrogen bonds with N1···H3A = 1.96 (2) Å and O3···H6 = 2.548 (9) Å, where the corresponding angles were measured at O3—H3A···N1 = 178 (15)° and C6—H6···O3 = 148.6 (3)°, respectively. Hydrogen-bond geometries for (1) are summarized in Table 1.

The isostructural iodo derivative (2) was crystallized from di­chloro­methane with no evidence of co-crystallized solvent. Again, an anti­periplanar orientation of the 2-oxazolinyl moieties within the molecular structure (Fig. 2) was found. In contrast to (1), a more distinct twisting of the planes N1/C7/O1 and N2/C12/O2 compared to the plane B with inter­planar angles of 16.16 (4) and 15.14 (4)°, respectively, was found.

For (2), similar conformational considerations as for (1) apply. Puckering parameters τm = 19.6 (1)°, q2 = 0.1902 (11) Å, and φ2 = 135.5 (3)° indicate a conformation between C8TC9 and C8E for ring C. A higher degree of planarity was found for ring A with τm = 4.6 (1)°. The bond length C5—I1 is 2.0968 (9) Å with I1 located 0.1183 (14) Å above ring B and thus considerably more distant than the bromine atom in (1), where Br1 lies only 0.005 (2) Å above plane B. The deviation occurs away from a ππ stacked (see also below) inversion-equivalent formula unit and might be the consequence of steric repulsion between the extensive iodine substituent and the 2-oxazolinyl groups of the neighboring formula unit. Noteworthy deviations from ideal angles within ring B were found with C4—C5—C6 = 121.35 (9)° and C3—C4—C5 = 118.60 (9)°. I1 shows an angular adjustment to C6—C5—I1 = 117.08 (7)°, thus improving inter­molecular N···I contacts (see below).

All bond lengths for (1) and (2) fall within expected ranges (Allen et al., 1987).

Supra­molecular features top

Within the crystal structure of (1) (Fig. 3), inter­molecular bonding is established by classical and non-classical hydrogen bonding (see Table 1) as well as ππ inter­actions. Close contacts O3···H16Bi = 2.181 (10) Å with C16i—H16Bi···O3 = 146.2 (3)° and H13B···O3i = 2.936 (11) Å with C13—H13B···O3i = 130.4 (3)° were found. Further hydrogen-bonding inter­actions arise from mutual inter­actions of two inversion-related water molecules with H3B···O3iii = 2.32 (13) Å and O3—H3B···O3iii = 126 (13)°.

Additionally, parallel-displaced ππ stacking with Cg1···Cg1i = 3.5064 (12) Å (Cg1 denotes the centroid calculated for the arene atoms) and a horizontal displacement of I = 0.996 (2) Å (for a description of geometric parameters of ππ associated arenes, see: Snyder et al., 2012) between the centroids was found. The inter­planar distance is R = 3.3620 (13) Å. The ππ inter­action gives rise to anti­periplanar dimers linked to each other by an inversion. Features of inter­molecular bonding for (1) are illustrated in Figure 4.

The supra­molecular contacts found for (2) are depicted in Fig. 5. A comparable ππ stacking motif as for compound (1) was found within the crystal structure of (2) (Fig. 6). The centroid–centroid distance Cg1···Cg1i = 3.6142 (8) Å is slightlny increased compared to (1). The inter­planar distance is R = 3.2862 (9) Å with a remarkably increased horizontal centroid–centroid displacement of I = 1.5044 (15) Å.

Mutual hydrogen bonds I1···H6ii = I1ii···H6 = 3.11 Å with C6—H6···I1ii = C6ii—H6ii···I1 = 150° and H10B···N2ii = 2.745 Å with an angle of C10—H10B···N2ii = 172° establish inter­molecular bonding. Additionally, particularly short mutual N1···I1ii and N1ii···I1 contacts at 3.2779 (9) Å were found. The N···I distance corresponds to 89 % of the sum of the van der Waals radii (3.70 Å; Alvarez, 2013) of the atoms involved. To the best of our knowledge, the shortest N···I contact found in a crystal structure was recently reported to be 2.622 Å (Bosch, 2014), corresponding to 71 % of the sum of the van der Waals radii. With respect to I1···N1ii contacts, the angle C5—I1···N1ii = 155.61 (3)° is found to be slightly linearized by an angular adaption C6—C5—I1 (see above).

The halogen-halogen distances for (1) and (2) exceed the sum of the van der Waals radii and lack appropriate angles for halogen–halogen bonding.

Database survey top

The crystal structure of the reagent used to prepare compounds (1) and (2) (see also below), 5-bromo-1,3-di­cyano­benzene, has been published recently (CCDC reference number DIRLEX; Seidel et al., 2013).

A WebCSD search (Version 1.1.1, updated July 2015; Groom & Allen, 2014) for the 1,3-bis­(1,3-oxazolin-2-yl)benzene substructure gave 143 hits. Very few of the crystal structures show the parent motif without any metal ion bound to it. The following considerations take into account only purely organic structures with a 1,3-substitutional pattern, although a significant number of (metal coordinated) 1,3,5-tri(1,3-oxazolin-2-yl)benzenes has been reported.

1-Iodo-2,6-bis­(4'-iso­propyl-1,3-oxazolin-2-yl)-4-tert-butyl­benzene (ROHMIL; Bugarin & Connell, 2008) and 1,3-bis­(4,4-di­methyl-1,3-oxazolin-2-yl)-2-(tri­methyl­stannyl)benzene (FILNAQ; Stol et al., 2005) show substitutional variation from compounds (1) and (2). By introducing sterically demanding substituents ortho to the 1,3-oxazolin-2-yl groups, these are considerably more twisted against the parent arene ring plane with twisting angles ranging from 47.3 (2)–63.6 (2)° and 22.35 (8)–22.75 (8)° for the iodo and tin derivatives, respectively. The more distinct twisting of the respective groups in (2) with 16.16 (4) and 15.14 (4)° compared to (1) [2.15 (12) and 3.67 (16)°] might be attributed to geometrical requirements for the formation of supra­molecular bonding observed for (2). 1-Iodo-2,6-bis­(4'-iso­propyl-1,3-oxazolin-2-yl)-4-tert-butyl­benzene shows short N···I distances at 3.041 (6) Å corresponding to 82 % of the sum of van der Waals radii.

Other structures generally lack halide substitution at the central arene, although substitutional variety at the 4'-positions was found. Instead of 4,4-di­methyl substitution, derivatives bearing hydrogen atoms (LAFNEM; Chen et al., 2004), hy­droxy­methyl (MODQIH; Javadi et al., 2014) or iso­propyl groups (DOWGOM; Mei et al., 2009) have been found. For those structures, no features of inter­molecular ππ inter­actions could be observed. Instead, C—H···π inter­action becomes obvious for LAFNEM and DOWGOM. It is supposed that halide substitution increases dispersion inter­action at modest horizontal centroid-centroid separations (Arnstein & Sherrill, 2008), thus promoting ππ stacking for (1) and (2). As a result of the presence of electronegative atoms, hydrogen bonding and van der Waals contacts can also be found for the structures mentioned.

Structures DOWGOM, FILNAQ, MODQIH, and ROHMIL show a synperiplanar orientation of the 2-oxazolinyl groups. The anti­periplanar arrangement as in (1) and (2) was only found for LAFNEM.

Langer et al. found the same C8TC9 conformation (with respect to the numbering scheme used herein) within the 2-oxazoline ring of 2-(4-hy­droxy­phenyl)-4,4-di­methyl-2-oxazoline (CELMAI; Langer et al., 2006) as for the 2-oxazoline moieties in (1) and (2). Conformational analysis of the 2-oxazolines within the structures discussed herein showed that all possible conformations twisted around C8—C9 can be found, that are C8TC9 (two times within DOWGOM, CELMAI) and C9TC8 (LAWCAO, ROHMIL). Folding into an envelope conformation was only observed at C8 with examples for C8E (two times within DOWGOM, ROHMIL) and EC8 (FILNAQ, two times within ROHMIL) conformations. This might suggest that folding happens preferentially at the less-substituted methyl­ene position. Planar conformations have been found for MODQIH, LAFNEM, and FILNAQ.

Synthesis and crystallization top

(1) and (2) were synthesized starting from 5-bromo-1,3-di­cyano­benzene (Fig. 7). The multi-step preparation of 5-bromo-1,3-di­cyano­benzene starting from isophthalic acid has been described in a patent (Dillard et al., 2010). For the preparation of compound (1), 5-bromo-1,3-di­cyano­benzene was subjected to cyclization at the cyano positions with 2-amino-2-methyl­propan-1-ol under zinc(II) catalysis (Button et al., 2002) to give the meta-bis­(1,3-oxazolin-2-yl) arene. The iodo derivative (2) was synthesized from (1) by an aromatic Finkelstein reaction (Klapars & Buchwald, 2002). All reactions were carried out under an atmosphere of dry nitro­gen using standard Schlenk techniques.

1-Bromo-3,5-bis­(4,4-di­methyl-1,3-oxazolin-2-yl)benzene sub-hydrate (1) top

Zinc(II) chloride (73 mg, 0.54 mmol, 0.1 eq.) was melted three times in vacuo with help of a heat gun. 5-Bromo-1,3-di­cyano­benzene (1.13 g, 4.65 mmol, 1.0 eq.), 2-amino-2-methyl­propan-1-ol (870 mg, 9.77 mmol, 2.1 eq.) and chloro­benzene (15 mL) were added, the colorless suspension was magnetically stirred and heated to reflux for 48 h where it became a pink-colored solution. After qu­anti­tative conversion of the di­cyano compound was confirmed via TLC, the reaction mixture was cooled to 353 K. Volatiles were removed in vacuo at 353–433K. After cooling to room temperature, di­chloro­methane (50 mL) and distilled water (50 mL) were added. The organic layer was separated, the aqueous layer extracted with di­chloro­methane (three times with 20 mL each). The combined organic layers were dried over sodium sulfate, filtered, and the solvent was removed from the filtrate under reduced pressure. Column chromatography of the crude product (SiO2; petrol ether/ethyl acetate = 4:1) gave (1) (1.52 g, 4.33 mmol, 93 %) as a colorless solid. Crystallization of (1) from a concentrated solution in aceto­nitrile at 277 K gave single crystals suitable for X-ray structural analysis.

1H-NMR (DMSO-d6, 300.21 MHz): δ (p.p.m.) = 8.28 (t, 1H; 4J(H,H) = 1.5 Hz, H2), 8.06 (d, 2H; 4J(H,H) = 1.5 Hz, H4, H6), 4.16 (s, 4H; H8, H13), 1.30 (s, 12H; H10, H11, H15, H16). 13C{1H}-NMR (DMSO-d6, 75.50 MHz): δ (p.p.m.) = 158.7 (C7, C12), 132.5 (C4, C6), 130.1 (C1, C3), 126.0 (C2), 121.9 (C5), 78.9 (C8, C13), 67.7 (C9, C14), 28.1 (C10, C11, C15, C16). ESI–HRMS(+) m/z: calculated for [M+H]+ 351.0703/353.0688, found 351.0707/353.0689 (79Br/81Br).

1-Iodo-3,5-bis­(4,4-di­methyl-1,3-oxazolin-2-yl)benzene (2) top

A J. Young ampoule was charged with (1) (500 mg, 1.42 mmol, 1.0 eq.), copper(I) iodide (14 mg, 74 µmol, 5 mol%), and sodium iodide (426 mg, 2.84 mmol, 2.0 eq.). The ampoule was put to vacuum und flushed with nitro­gen three times. 1,4-Dioxane (3 mL) and N,N'-di­methyl­ethylenedi­amine (15 µL, 0.14 mmol, 10 mol%) were added. The ampoule was sealed with a Teflon screw valve, the colorless suspension was magnetically stirred and heated to 373 K for 24 h. An intense blue coloring was observed during the reaction course. After cooling to room temperature, ammonia solution (10 mL, 25 %), distilled water (20 mL), and di­chloro­methane (30 mL) were added. The organic layer was separated, the aqueous layer extracted with di­chloro­methane (three times with 10 mL each) and the combined organic phases were dried over sodium sulfate. After filtration, di­chloro­methane was removed from the filtrate under reduced pressure. The crude product was purified by means of column chromatography (SiO2; petrol ether/ethyl acetate = 4:1) to give a colorless solid (2) (505 mg, 1.27 mmol, 89 %). Crystallization from a concentrated solution of (2) in di­chloro­methane by slow evaporation of the solvent yielded single crystals suitable for X-ray single crystal diffraction.

1H-NMR (DMSO-d6, 300.21 MHz): δ (p.p.m.) = 8.28 (t, 1H; 4J(H,H) = 1.5 Hz, H2), 8.24 (d, 2H; 4J(H,H) = 1.5 Hz, H4, H6), 4.14 (s, 4H; H8, H13), 1.29 (s, 12H; H10, H11, H15, H16). 13C{1H}-NMR (DMSO-d6, 75.50 MHz): δ (p.p.m.) = 158.6 (C7, C12), 138.2 (C1, C3), 132.5 (C4, C6), 129.8 (C2), 126.2 (C1), 78.8 (C8, C13), 67.7 (C9, C14), 28.1 (C10, C11, C15, C16). EI–MS m/z: calcd. for M+. 398.08, found 398.08 (M+.), 383.06 (M+. – CH3.), 368.07 (M+. – 2CH3.).

Refinement top

Crystal data, data collection, and structure refinement details are summarized in Table 3.

Primary atom site locations were assigned with EDMA (Palatinus et al., 2012) from electron densities obtained by SUPERFLIP (Palatinus & Chapuis, 2007). The remaining secondary non-carbon atom sites were located from the difference Fourier map. All non-hydrogen atoms were refined with anisotropic displacement parameters.

Full-matrix least-squares refinement on F2 was done with SHELXL2014/7 (Sheldrick, 2008). Carbon-bound hydrogen atoms were positioned geometrically and refined riding on their respective carbon atom. Bond lengths were fixed at 0.95 Å (aromatic H), 0.98 Å (methyl H), and 0.99 Å (methyl­ene H). Uiso(H) was fixed at 1.5 Ueq(O) and Ueq(C) for hydroxyl and methyl hydrogens or 1.2 Ueq(C) for the remaining hydrogens. Methyl hydrogens were fitted to the experimental electron density by allowing them to rotate around the C—C bond with a fixed angle (HFIX 137).

For (1), occupancy refinement of O3 gave an occupancy of 0.15543 (611) which was subsequently fixed at 0.15. The hydrogens H3A and H3B were located with the help of CALC-OH, which is the WinGX (Farrugia, 2012) implementation of Nardelli's method (Nardelli, 1999) of OH atom positioning. The coordinates of those hydrogen atoms were refined freely while applying restraints to the overall water geometry (O—H = 0.84 Å and H···H = 1.328 Å).

Computing details top

Data collection: CrysAlis PRO (Agilent, 2013) for (1); APEX2 (Bruker, 2014) for (2). Cell refinement: CrysAlis PRO (Agilent, 2013) for (1); SAINT (Bruker, 2014) for (2). Data reduction: CrysAlis PRO (Agilent, 2013) for (1); SAINT (Bruker, 2014) for (2). For both compounds, program(s) used to solve structure: SUPERFLIP (Palatinus & Chapuis, 2007); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: WinGX (Farrugia, 2012), OLEX2 (Dolomanov et al., 2009), publCIF (Westrip, 2010) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The asymmetric unit of (1), shown with 50% probability displacement ellipsoids. H atoms are drawn as green spheres of an arbitrary radius.
[Figure 2] Fig. 2. The asymmetric unit of (2), shown with displacement ellipsoids drawn at the 50% probability level. H atoms are drawn as green spheres of arbitrary radius.
[Figure 3] Fig. 3. View along the a axis of the crystal packing of compound (1).
[Figure 4] Fig. 4. Intermolecular contacts within the crystal structure of (1) are established by means of parallel-displaced ππ interactions and hydrogen bonding. Displacement ellipsoids are at the 50% probability level and intermolecular contacts are depicted as dashed lines. Only H atoms involved in hydrogen bonding or van der Waals contacts (black dashed lines) are shown as green spheres at an arbitrary radius. Purple dashed lines indicate centroid–centroid connecting lines. [Symmetry codes: (i) -x + 1, -y + 1, -z + 1; (ii) -x + 1/2, y + 1/2, -z + 1/2; (iii) x - 1/2, -y + 3/2, z - 1/2.]
[Figure 5] Fig. 5. Supramolecular features within the crystal structure of (2) comprise ππ contacts and mutual N1···I1ii and N1ii···I1 interactions. Moreover, there are non-conventional hydrogen bonds I1ii···H6, I1···H6ii, and H10B···N2iii. Intermolecular contacts are shown as dashed lines. Only atoms H6, H6ii, and H10B which are involved in hydrogen bonding (black dashed lines) are shown as green spheres of an arbitrary radius. Purple dashed lines connect centroids of ππ associated dimers. [Symmetry codes: (i) -x + 1, -y + 1, -z + 1; (ii) -x + 1, -y + 2, -z + 1; (iii) -x + 3/2, y + 1/2, -z + 1/2.]
[Figure 6] Fig. 6. View along the a axis of the crystal packing of compound (2).
[Figure 7] Fig. 7. The synthesis scheme of (1) and (2), starting from 1-bromo-3,5-dicyanobenzene. The numbering scheme for the title compounds is given.
(1) 1-Bromo-3,5-bis(4,4-dimethyl-1,3-oxazolin-2-yl)benzene 0.15-hydrate top
Crystal data top
C16H19BrN2O2·0.15H2OF(000) = 726
Mr = 353.94Dx = 1.427 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
a = 10.0661 (1) ÅCell parameters from 11733 reflections
b = 16.2960 (2) Åθ = 3.2–31.8°
c = 11.0400 (1) ŵ = 2.50 mm1
β = 114.496 (2)°T = 100 K
V = 1647.96 (4) Å3Plate, colorless
Z = 40.34 × 0.26 × 0.08 mm
Data collection top
Agilent SuperNova Dual Source
diffractometer with an Atlas detector
5438 independent reflections
Radiation source: SuperNova (Mo) X-ray Source4598 reflections with I > 2σ(I)
Mirror monochromatorRint = 0.035
Detector resolution: 10.4127 pixels mm-1θmax = 31.5°, θmin = 3.2°
ω scansh = 1414
Absorption correction: multi-scan
(CrysAlis PRO; Agilent, 2013)
k = 2323
Tmin = 0.670, Tmax = 1.000l = 1616
29541 measured reflections
Refinement top
Refinement on F2Primary atom site location: iterative
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.035Hydrogen site location: mixed
wR(F2) = 0.080H atoms treated by a mixture of independent and constrained refinement
S = 1.05 w = 1/[σ2(Fo2) + (0.0278P)2 + 1.5569P]
where P = (Fo2 + 2Fc2)/3
5438 reflections(Δ/σ)max = 0.001
209 parametersΔρmax = 0.85 e Å3
3 restraintsΔρmin = 0.74 e Å3
Crystal data top
C16H19BrN2O2·0.15H2OV = 1647.96 (4) Å3
Mr = 353.94Z = 4
Monoclinic, P21/nMo Kα radiation
a = 10.0661 (1) ŵ = 2.50 mm1
b = 16.2960 (2) ÅT = 100 K
c = 11.0400 (1) Å0.34 × 0.26 × 0.08 mm
β = 114.496 (2)°
Data collection top
Agilent SuperNova Dual Source
diffractometer with an Atlas detector
5438 independent reflections
Absorption correction: multi-scan
(CrysAlis PRO; Agilent, 2013)
4598 reflections with I > 2σ(I)
Tmin = 0.670, Tmax = 1.000Rint = 0.035
29541 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0353 restraints
wR(F2) = 0.080H atoms treated by a mixture of independent and constrained refinement
S = 1.05Δρmax = 0.85 e Å3
5438 reflectionsΔρmin = 0.74 e Å3
209 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger. All non-hydrogen atoms were refined with anisotropic displacement parameters. Carbon-bound hydrogen atoms were positioned geometrically and refined riding on their respective carbon atom. Bond lengths were fixed at 0.95 Å (aromatic H), 0.98 Å (methyl H), and 0.99 Å (methylene H). Uiso(H) was fixed at 1.5 Ueq(O) and Ueq(C) for hydroxyl and methyl H atoms or 1.2 Ueq(C) for the remaining H atoms. Methyl H atoms were fitted to the experimental electron density by allowing them to rotate around the C–C bond with a fixed angle (HFIX 137). Occupancy refinement of O3 gave an occupancy of 0.15543 (611) which was subsequently fixed at 0.15. The H atoms H3A and H3B were located with help of CALC-OH which is the WinGX (Farrugia, 2012) implementation of Nardelli's method (Nardelli, 1999) of OH atom positioning. The coordinates of those H atoms were refined freely while applying restraints to the overall water geometry (O–H = 0.84 Å and H···H = 1.328 Å).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
C10.26376 (17)0.48374 (9)0.34172 (15)0.0162 (3)
C30.44468 (17)0.38604 (9)0.47611 (15)0.0161 (3)
C50.45798 (18)0.44445 (10)0.28229 (15)0.0180 (3)
C40.51639 (17)0.39301 (10)0.39218 (15)0.0176 (3)
H40.60350.36310.40990.021*
C120.49957 (17)0.32940 (10)0.59022 (16)0.0184 (3)
C70.13236 (18)0.53354 (9)0.31540 (15)0.0172 (3)
C60.33230 (18)0.48959 (10)0.25469 (15)0.0179 (3)
H60.29340.52380.17830.022*
C90.0526 (2)0.62058 (12)0.23624 (19)0.0268 (4)
C140.53332 (19)0.25360 (11)0.76730 (17)0.0226 (3)
C160.4386 (3)0.18050 (16)0.7561 (4)0.0682 (10)
H16A0.49620.13800.81860.102*
H16B0.40090.15890.66510.102*
H16C0.35680.19680.77710.102*
C150.5965 (4)0.28651 (17)0.9079 (2)0.0632 (9)
H15A0.65900.24470.96870.095*
H15B0.51700.30040.93360.095*
H15C0.65440.33570.91270.095*
C20.31925 (17)0.43183 (9)0.45143 (15)0.0159 (3)
H20.27160.42760.50960.019*
C130.6535 (3)0.2366 (2)0.7218 (3)0.0757 (12)
H13A0.74950.25310.79140.091*
H13B0.65680.17750.70280.091*
C80.0606 (2)0.57193 (12)0.35229 (19)0.0257 (4)
H8A0.06760.60940.42010.031*
H8B0.14600.53470.32030.031*
C100.0128 (3)0.70964 (14)0.2754 (3)0.0525 (7)
H10A0.09250.73640.28940.079*
H10B0.00310.73800.20430.079*
H10C0.07660.71200.35780.079*
C110.1925 (3)0.6130 (2)0.1101 (2)0.0564 (8)
H11A0.27550.63040.12830.085*
H11C0.20610.55580.08010.085*
H11B0.18590.64790.04050.085*
N20.44454 (16)0.31821 (9)0.67357 (14)0.0217 (3)
N10.07115 (17)0.58157 (10)0.21786 (15)0.0248 (3)
O20.61878 (15)0.28455 (9)0.60266 (13)0.0309 (3)
O10.07500 (14)0.52563 (8)0.40654 (13)0.0257 (3)
Br10.55330 (2)0.45321 (2)0.16706 (2)0.02642 (6)
O30.0751 (12)0.5663 (7)0.0328 (10)0.035 (2)0.15
H3A0.076 (18)0.572 (11)0.043 (8)0.050*0.15
H3B0.010 (15)0.532 (9)0.071 (14)0.050*0.15
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0199 (7)0.0131 (6)0.0129 (6)0.0033 (5)0.0042 (5)0.0015 (5)
C30.0180 (7)0.0150 (7)0.0121 (6)0.0028 (5)0.0030 (5)0.0007 (5)
C50.0211 (7)0.0192 (7)0.0136 (6)0.0068 (6)0.0072 (6)0.0031 (6)
C40.0180 (7)0.0174 (7)0.0148 (7)0.0036 (5)0.0042 (6)0.0034 (5)
C120.0174 (7)0.0176 (7)0.0172 (7)0.0005 (6)0.0041 (6)0.0016 (6)
C70.0211 (7)0.0143 (7)0.0148 (6)0.0027 (5)0.0060 (6)0.0007 (5)
C60.0227 (7)0.0157 (7)0.0123 (6)0.0040 (6)0.0042 (6)0.0002 (5)
C90.0225 (8)0.0287 (9)0.0283 (9)0.0055 (7)0.0098 (7)0.0115 (7)
C140.0214 (8)0.0232 (8)0.0218 (8)0.0059 (6)0.0075 (6)0.0091 (6)
C160.0363 (13)0.0327 (12)0.097 (2)0.0059 (10)0.0107 (13)0.0361 (14)
C150.091 (2)0.0425 (14)0.0272 (11)0.0238 (14)0.0041 (13)0.0066 (10)
C20.0195 (7)0.0135 (6)0.0131 (6)0.0025 (5)0.0054 (5)0.0011 (5)
C130.0707 (19)0.115 (3)0.0664 (18)0.071 (2)0.0532 (16)0.0711 (19)
C80.0246 (8)0.0265 (8)0.0263 (9)0.0063 (7)0.0108 (7)0.0070 (7)
C100.0556 (15)0.0216 (10)0.097 (2)0.0112 (10)0.0485 (16)0.0155 (12)
C110.0293 (11)0.099 (2)0.0326 (12)0.0073 (13)0.0045 (9)0.0261 (14)
N20.0229 (7)0.0216 (7)0.0193 (6)0.0065 (5)0.0075 (5)0.0086 (5)
N10.0263 (7)0.0266 (8)0.0202 (7)0.0060 (6)0.0084 (6)0.0076 (6)
O20.0269 (7)0.0420 (8)0.0269 (7)0.0164 (6)0.0143 (5)0.0178 (6)
O10.0260 (6)0.0299 (7)0.0245 (6)0.0090 (5)0.0138 (5)0.0126 (5)
Br10.02744 (9)0.03482 (10)0.02055 (9)0.00288 (7)0.01352 (7)0.00215 (7)
O30.039 (5)0.040 (6)0.024 (4)0.002 (4)0.011 (4)0.003 (4)
Geometric parameters (Å, º) top
C1—C21.391 (2)C14—C131.515 (3)
C1—C61.399 (2)C16—H16A0.9800
C1—C71.474 (2)C16—H16B0.9800
C3—C21.393 (2)C16—H16C0.9800
C3—C41.396 (2)C15—H15A0.9800
C3—C121.472 (2)C15—H15B0.9800
C5—C61.384 (2)C15—H15C0.9800
C5—C41.389 (2)C2—H20.9500
C5—Br11.8898 (16)C13—O21.443 (3)
C4—H40.9500C13—H13A0.9900
C12—N21.269 (2)C13—H13B0.9900
C12—O21.362 (2)C8—O11.454 (2)
C7—N11.266 (2)C8—H8A0.9900
C7—O11.358 (2)C8—H8B0.9900
C6—H60.9500C10—H10A0.9800
C9—N11.485 (2)C10—H10B0.9800
C9—C101.520 (3)C10—H10C0.9800
C9—C111.520 (3)C11—H11A0.9800
C9—C81.537 (3)C11—H11C0.9800
C14—N21.487 (2)C11—H11B0.9800
C14—C161.498 (3)O3—H3A0.84 (2)
C14—C151.511 (3)O3—H3B0.84 (2)
C2—C1—C6120.34 (15)C14—C15—H15A109.5
C2—C1—C7120.67 (14)C14—C15—H15B109.5
C6—C1—C7118.99 (14)H15A—C15—H15B109.5
C2—C3—C4120.20 (14)C14—C15—H15C109.5
C2—C3—C12119.44 (14)H15A—C15—H15C109.5
C4—C3—C12120.35 (14)H15B—C15—H15C109.5
C6—C5—C4122.04 (15)C1—C2—C3120.03 (15)
C6—C5—Br1118.98 (12)C1—C2—H2120.0
C4—C5—Br1118.98 (13)C3—C2—H2120.0
C5—C4—C3118.75 (15)O2—C13—C14106.17 (16)
C5—C4—H4120.6O2—C13—H13A110.5
C3—C4—H4120.6C14—C13—H13A110.5
N2—C12—O2118.75 (15)O2—C13—H13B110.5
N2—C12—C3126.08 (15)C14—C13—H13B110.5
O2—C12—C3115.16 (14)H13A—C13—H13B108.7
N1—C7—O1118.85 (15)O1—C8—C9104.25 (14)
N1—C7—C1126.06 (15)O1—C8—H8A110.9
O1—C7—C1115.09 (13)C9—C8—H8A110.9
C5—C6—C1118.59 (14)O1—C8—H8B110.9
C5—C6—H6120.7C9—C8—H8B110.9
C1—C6—H6120.7H8A—C8—H8B108.9
N1—C9—C10108.11 (16)C9—C10—H10A109.5
N1—C9—C11110.53 (19)C9—C10—H10B109.5
C10—C9—C11111.9 (2)H10A—C10—H10B109.5
N1—C9—C8103.30 (14)C9—C10—H10C109.5
C10—C9—C8110.73 (19)H10A—C10—H10C109.5
C11—C9—C8111.89 (17)H10B—C10—H10C109.5
N2—C14—C16109.10 (15)C9—C11—H11A109.5
N2—C14—C15109.82 (16)C9—C11—H11C109.5
C16—C14—C15110.5 (2)H11A—C11—H11C109.5
N2—C14—C13103.34 (15)C9—C11—H11B109.5
C16—C14—C13113.3 (3)H11A—C11—H11B109.5
C15—C14—C13110.6 (2)H11C—C11—H11B109.5
C14—C16—H16A109.5C12—N2—C14106.82 (14)
C14—C16—H16B109.5C7—N1—C9106.76 (15)
H16A—C16—H16B109.5C12—O2—C13104.63 (15)
C14—C16—H16C109.5C7—O1—C8105.11 (13)
H16A—C16—H16C109.5H3A—O3—H3B105 (5)
H16B—C16—H16C109.5
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C6—H6···O30.952.55 (1)3.395 (10)149 (1)
O3—H3A···N10.84 (2)1.96 (2)2.796 (10)178 (15)
C16—H16B···O3i0.982.18 (1)3.045 (11)146 (1)
C13—H13B···O3i0.992.94 (1)3.656 (12)130 (1)
C8—H8B···Br1ii0.993.09 (1)4.054 (2)165 (1)
C11—H11C···O3iii0.982.56 (1)3.391 (12)143 (1)
O3—H3B···N1iii0.84 (2)2.37 (9)3.107 (11)148 (15)
O3—H3B···O3iii0.84 (2)2.32 (13)2.90 (2)126 (13)
Symmetry codes: (i) x+1/2, y1/2, z+1/2; (ii) x1, y, z; (iii) x, y+1, z.
(2) 3,5-Bis(4,4-dimethyl-1,3-oxazolin-2-yl)-1-iodobenzene top
Crystal data top
C16H19IN2O2F(000) = 792
Mr = 398.23Dx = 1.599 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
a = 9.6195 (2) ÅCell parameters from 9629 reflections
b = 9.9759 (2) Åθ = 2.3–34.2°
c = 17.2951 (4) ŵ = 1.94 mm1
β = 94.648 (1)°T = 100 K
V = 1654.23 (6) Å3Block, colorless
Z = 40.22 × 0.12 × 0.08 mm
Data collection top
Bruker SMART APEX CCD area-detector
diffractometer
6463 independent reflections
Radiation source: Incoatec microfocus6035 reflections with I > 2σ(I)
Mirror monochromatorRint = 0.019
ω scansθmax = 33.5°, θmin = 2.4°
Absorption correction: numerical
(SADABS; Bruker, 2014)
h = 1414
Tmin = 0.649, Tmax = 0.747k = 1515
45346 measured reflectionsl = 2626
Refinement top
Refinement on F2Primary atom site location: iterative
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.017Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.043H-atom parameters constrained
S = 1.07 w = 1/[σ2(Fo2) + (0.0189P)2 + 0.8336P]
where P = (Fo2 + 2Fc2)/3
6463 reflections(Δ/σ)max = 0.007
194 parametersΔρmax = 0.82 e Å3
0 restraintsΔρmin = 0.62 e Å3
Crystal data top
C16H19IN2O2V = 1654.23 (6) Å3
Mr = 398.23Z = 4
Monoclinic, P21/nMo Kα radiation
a = 9.6195 (2) ŵ = 1.94 mm1
b = 9.9759 (2) ÅT = 100 K
c = 17.2951 (4) Å0.22 × 0.12 × 0.08 mm
β = 94.648 (1)°
Data collection top
Bruker SMART APEX CCD area-detector
diffractometer
6463 independent reflections
Absorption correction: numerical
(SADABS; Bruker, 2014)
6035 reflections with I > 2σ(I)
Tmin = 0.649, Tmax = 0.747Rint = 0.019
45346 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0170 restraints
wR(F2) = 0.043H-atom parameters constrained
S = 1.07Δρmax = 0.82 e Å3
6463 reflectionsΔρmin = 0.62 e Å3
194 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger. All non-hydrogen atoms were refined with anisotropic displacement parameters. Carbon-bound hydrogen atoms were positioned geometrically and refined riding on their respective carbon atom. Bond lengths were fixed at 0.95 Å (aromatic H), 0.98 Å (methyl H), and 0.99 Å (methylene H). Uiso(H) was fixed at 1.5 Ueq(O) and Ueq(C) for hydroxyl and methyl H atoms or 1.2 Ueq(C) for the remaining H atoms. Methyl H atoms were fitted to the experimental electron density by allowing them to rotate around the C–C bond with a fixed angle (HFIX 137).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C10.56410 (10)0.66623 (9)0.41768 (5)0.01116 (15)
C20.48728 (10)0.55181 (9)0.39654 (5)0.01198 (15)
H20.52320.48780.36270.014*
C30.35754 (10)0.53146 (9)0.42507 (5)0.01135 (15)
C40.30480 (10)0.62363 (9)0.47619 (6)0.01244 (16)
H40.21790.60830.49710.015*
C50.38251 (10)0.73850 (9)0.49576 (6)0.01210 (15)
C60.51110 (10)0.76077 (9)0.46704 (6)0.01225 (15)
H60.56260.83970.48080.015*
C70.70012 (10)0.69002 (9)0.38670 (5)0.01184 (15)
C80.89158 (12)0.62676 (11)0.33104 (8)0.0221 (2)
H8A0.89990.60780.27540.027*
H8B0.96940.58220.36210.027*
C90.89278 (10)0.77946 (10)0.34634 (6)0.01420 (16)
C100.88285 (14)0.85997 (15)0.27141 (7)0.0273 (2)
H10A0.80130.83040.23810.041*
H10B0.96740.84600.24440.041*
H10C0.87350.95540.28340.041*
C111.01869 (12)0.82249 (13)0.39920 (7)0.0236 (2)
H11A1.01070.91790.41160.035*
H11B1.10380.80740.37290.035*
H11C1.02270.76990.44720.035*
C120.27785 (10)0.41157 (10)0.39882 (6)0.01243 (16)
C130.12395 (12)0.24676 (11)0.40919 (6)0.0201 (2)
H13A0.02110.24090.40040.024*
H13B0.15750.17470.44540.024*
C140.19275 (12)0.23620 (11)0.33195 (6)0.01761 (18)
C150.09128 (15)0.27569 (14)0.26324 (7)0.0281 (3)
H15A0.05210.36430.27270.042*
H15B0.01580.20970.25700.042*
H15C0.14080.27840.21590.042*
C160.25716 (16)0.09954 (12)0.31923 (9)0.0299 (3)
H16A0.30900.10230.27280.045*
H16B0.18320.03200.31240.045*
H16C0.32080.07620.36430.045*
N10.76407 (9)0.80152 (9)0.38642 (5)0.01435 (15)
N20.30375 (10)0.33974 (9)0.34100 (5)0.01682 (16)
O10.75825 (9)0.58108 (8)0.35446 (5)0.01984 (15)
O20.16674 (9)0.37812 (8)0.43947 (5)0.01763 (15)
I10.30572 (2)0.88951 (2)0.56511 (2)0.01650 (2)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0122 (4)0.0101 (4)0.0111 (4)0.0011 (3)0.0008 (3)0.0002 (3)
C20.0144 (4)0.0106 (4)0.0109 (4)0.0012 (3)0.0007 (3)0.0008 (3)
C30.0130 (4)0.0099 (4)0.0108 (4)0.0018 (3)0.0007 (3)0.0001 (3)
C40.0125 (4)0.0113 (4)0.0134 (4)0.0008 (3)0.0006 (3)0.0002 (3)
C50.0132 (4)0.0102 (4)0.0130 (4)0.0003 (3)0.0016 (3)0.0017 (3)
C60.0134 (4)0.0101 (4)0.0132 (4)0.0011 (3)0.0008 (3)0.0012 (3)
C70.0133 (4)0.0111 (4)0.0113 (4)0.0000 (3)0.0017 (3)0.0010 (3)
C80.0184 (5)0.0177 (5)0.0320 (6)0.0007 (4)0.0120 (4)0.0047 (4)
C90.0128 (4)0.0151 (4)0.0152 (4)0.0001 (3)0.0040 (3)0.0016 (3)
C100.0277 (6)0.0344 (6)0.0208 (5)0.0057 (5)0.0073 (4)0.0111 (5)
C110.0150 (5)0.0285 (6)0.0271 (5)0.0008 (4)0.0000 (4)0.0028 (4)
C120.0129 (4)0.0119 (4)0.0124 (4)0.0030 (3)0.0004 (3)0.0004 (3)
C130.0224 (5)0.0194 (5)0.0191 (5)0.0115 (4)0.0043 (4)0.0044 (4)
C140.0203 (5)0.0153 (4)0.0174 (4)0.0078 (4)0.0028 (4)0.0047 (3)
C150.0329 (6)0.0294 (6)0.0207 (5)0.0104 (5)0.0061 (5)0.0043 (4)
C160.0319 (7)0.0168 (5)0.0419 (7)0.0062 (4)0.0090 (6)0.0096 (5)
N10.0127 (3)0.0128 (3)0.0183 (4)0.0013 (3)0.0051 (3)0.0004 (3)
N20.0191 (4)0.0150 (4)0.0168 (4)0.0070 (3)0.0038 (3)0.0042 (3)
O10.0188 (4)0.0137 (3)0.0284 (4)0.0021 (3)0.0107 (3)0.0070 (3)
O20.0175 (3)0.0182 (4)0.0178 (3)0.0083 (3)0.0057 (3)0.0050 (3)
I10.01488 (3)0.01529 (3)0.01976 (4)0.00079 (2)0.00401 (2)0.00607 (2)
Geometric parameters (Å, º) top
C1—C21.3924 (13)C10—H10A0.9800
C1—C61.3959 (13)C10—H10B0.9800
C1—C71.4728 (13)C10—H10C0.9800
C2—C31.3936 (13)C11—H11A0.9800
C2—H20.9500C11—H11B0.9800
C3—C41.3990 (13)C11—H11C0.9800
C3—C121.4724 (13)C12—N21.2711 (13)
C4—C51.3948 (13)C12—O21.3675 (12)
C4—H40.9500C13—O21.4581 (13)
C5—C61.3878 (13)C13—C141.5418 (15)
C5—I12.0968 (9)C13—H13A0.9900
C6—H60.9500C13—H13B0.9900
C7—N11.2713 (12)C14—N21.4847 (13)
C7—O11.3620 (12)C14—C161.5209 (17)
C8—O11.4494 (14)C14—C151.5271 (17)
C8—C91.5460 (15)C15—H15A0.9800
C8—H8A0.9900C15—H15B0.9800
C8—H8B0.9900C15—H15C0.9800
C9—N11.4835 (13)C16—H16A0.9800
C9—C111.5191 (15)C16—H16B0.9800
C9—C101.5209 (15)C16—H16C0.9800
C2—C1—C6120.14 (9)H10B—C10—H10C109.5
C2—C1—C7120.32 (8)C9—C11—H11A109.5
C6—C1—C7119.53 (8)C9—C11—H11B109.5
C1—C2—C3119.86 (9)H11A—C11—H11B109.5
C1—C2—H2120.1C9—C11—H11C109.5
C3—C2—H2120.1H11A—C11—H11C109.5
C2—C3—C4120.60 (9)H11B—C11—H11C109.5
C2—C3—C12117.90 (8)N2—C12—O2118.56 (9)
C4—C3—C12121.49 (9)N2—C12—C3124.76 (9)
C5—C4—C3118.60 (9)O2—C12—C3116.67 (8)
C5—C4—H4120.7O2—C13—C14104.13 (8)
C3—C4—H4120.7O2—C13—H13A110.9
C6—C5—C4121.35 (9)C14—C13—H13A110.9
C6—C5—I1117.08 (7)O2—C13—H13B110.9
C4—C5—I1121.49 (7)C14—C13—H13B110.9
C5—C6—C1119.41 (9)H13A—C13—H13B108.9
C5—C6—H6120.3N2—C14—C16109.93 (10)
C1—C6—H6120.3N2—C14—C15108.15 (9)
N1—C7—O1118.80 (9)C16—C14—C15111.15 (10)
N1—C7—C1125.93 (9)N2—C14—C13102.51 (8)
O1—C7—C1115.26 (8)C16—C14—C13113.27 (10)
O1—C8—C9104.86 (8)C15—C14—C13111.38 (10)
O1—C8—H8A110.8C14—C15—H15A109.5
C9—C8—H8A110.8C14—C15—H15B109.5
O1—C8—H8B110.8H15A—C15—H15B109.5
C9—C8—H8B110.8C14—C15—H15C109.5
H8A—C8—H8B108.9H15A—C15—H15C109.5
N1—C9—C11109.38 (9)H15B—C15—H15C109.5
N1—C9—C10108.82 (9)C14—C16—H16A109.5
C11—C9—C10110.82 (10)C14—C16—H16B109.5
N1—C9—C8103.37 (8)H16A—C16—H16B109.5
C11—C9—C8112.08 (9)C14—C16—H16C109.5
C10—C9—C8112.05 (10)H16A—C16—H16C109.5
C9—C10—H10A109.5H16B—C16—H16C109.5
C9—C10—H10B109.5C7—N1—C9107.12 (8)
H10A—C10—H10B109.5C12—N2—C14106.86 (9)
C9—C10—H10C109.5C7—O1—C8105.40 (8)
H10A—C10—H10C109.5C12—O2—C13104.14 (8)
C6—C1—C2—C30.31 (14)C2—C3—C12—O2166.31 (9)
C7—C1—C2—C3178.83 (9)C4—C3—C12—O214.56 (14)
C1—C2—C3—C41.37 (14)O2—C13—C14—N218.91 (11)
C1—C2—C3—C12177.77 (9)O2—C13—C14—C16137.30 (10)
C2—C3—C4—C52.25 (14)O2—C13—C14—C1596.53 (10)
C12—C3—C4—C5176.86 (9)O1—C7—N1—C91.19 (13)
C3—C4—C5—C61.49 (14)C1—C7—N1—C9177.34 (9)
C3—C4—C5—I1175.31 (7)C11—C9—N1—C7124.42 (10)
C4—C5—C6—C10.15 (14)C10—C9—N1—C7114.38 (10)
I1—C5—C6—C1177.09 (7)C8—C9—N1—C74.88 (11)
C2—C1—C6—C51.07 (14)O2—C12—N2—C142.75 (13)
C7—C1—C6—C5179.60 (9)C3—C12—N2—C14175.98 (9)
C2—C1—C7—N1162.51 (10)C16—C14—N2—C12134.30 (11)
C6—C1—C7—N116.02 (15)C15—C14—N2—C12104.17 (11)
C2—C1—C7—O116.07 (13)C13—C14—N2—C1213.58 (12)
C6—C1—C7—O1165.40 (9)N1—C7—O1—C83.37 (13)
O1—C8—C9—N16.63 (11)C1—C7—O1—C8177.95 (9)
O1—C8—C9—C11124.30 (10)C9—C8—O1—C76.05 (12)
O1—C8—C9—C10110.37 (11)N2—C12—O2—C1310.14 (13)
C2—C3—C12—N214.94 (15)C3—C12—O2—C13171.02 (9)
C4—C3—C12—N2164.19 (10)C14—C13—O2—C1217.51 (11)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C6—H6···I1i0.953.113.9679 (9)150
C10—H10B···N2ii0.982.753.7228 (15)172
Symmetry codes: (i) x+1, y+2, z+1; (ii) x+3/2, y+1/2, z+1/2.
Hydrogen-bond geometry (Å, º) for (1) top
D—H···AD—HH···AD···AD—H···A
C6—H6···O30.952.548 (10)3.395 (10)148.6 (3)
O3—H3A···N10.84 (2)1.96 (2)2.796 (10)178 (15)
C16—H16B···O3i0.982.181 (10)3.045 (11)146.2 (3)
C13—H13B···O3i0.992.94 (1)3.656 (12)130.4 (3)
C8—H8B···Br1ii0.993.08869 (19)4.054 (2)165.38 (10)
C11—H11C···O3iii0.982.557 (11)3.391 (12)142.9 (3)
O3—H3B···N1iii0.84 (2)2.37 (9)3.107 (11)148 (15)
O3—H3B···O3iii0.84 (2)2.32 (13)2.90 (2)126 (13)
Symmetry codes: (i) x+1/2, y1/2, z+1/2; (ii) x1, y, z; (iii) x, y+1, z.
Hydrogen-bond geometry (Å, º) for (2) top
D—H···AD—HH···AD···AD—H···A
C6—H6···I1i0.953.113.9679 (9)150
C10—H10B···N2ii0.982.753.7228 (15)172
Symmetry codes: (i) x+1, y+2, z+1; (ii) x+3/2, y+1/2, z+1/2.

Experimental details

(1)(2)
Crystal data
Chemical formulaC16H19BrN2O2·0.15H2OC16H19IN2O2
Mr353.94398.23
Crystal system, space groupMonoclinic, P21/nMonoclinic, P21/n
Temperature (K)100100
a, b, c (Å)10.0661 (1), 16.2960 (2), 11.0400 (1)9.6195 (2), 9.9759 (2), 17.2951 (4)
β (°) 114.496 (2) 94.648 (1)
V3)1647.96 (4)1654.23 (6)
Z44
Radiation typeMo KαMo Kα
µ (mm1)2.501.94
Crystal size (mm)0.34 × 0.26 × 0.080.22 × 0.12 × 0.08
Data collection
DiffractometerAgilent SuperNova Dual Source
diffractometer with an Atlas detector
Bruker SMART APEX CCD area-detector
diffractometer
Absorption correctionMulti-scan
(CrysAlis PRO; Agilent, 2013)
Numerical
(SADABS; Bruker, 2014)
Tmin, Tmax0.670, 1.0000.649, 0.747
No. of measured, independent and
observed [I > 2σ(I)] reflections
29541, 5438, 4598 45346, 6463, 6035
Rint0.0350.019
(sin θ/λ)max1)0.7350.776
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.035, 0.080, 1.05 0.017, 0.043, 1.07
No. of reflections54386463
No. of parameters209194
No. of restraints30
H-atom treatmentH atoms treated by a mixture of independent and constrained refinementH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.85, 0.740.82, 0.62

Computer programs: CrysAlis PRO (Agilent, 2013), APEX2 (Bruker, 2014), SAINT (Bruker, 2014), SUPERFLIP (Palatinus & Chapuis, 2007), SHELXL2014 (Sheldrick, 2015), XP in SHELXTL (Sheldrick, 2008), WinGX (Farrugia, 2012), OLEX2 (Dolomanov et al., 2009), publCIF (Westrip, 2010) and PLATON (Spek, 2009).

 

Acknowledgements

The authors gratefully acknowledge the continuous support of Professor Ulrich Behrens, University of Hamburg, for helpful discussions concerning X-ray structural analysis.

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Volume 71| Part 10| October 2015| Pages 1125-1131
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