research communications\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 72| Part 5| May 2016| Pages 663-666
doi:10.1107/S2056989016005752

Crystal structure of 26-(4-methyl­phen­yl)-8,11,14,17-tetra­oxa-28-aza­tetra­cyclo[22.3.1.02,7.018,23]hexa­cosa-2,4,6,18(23),19,21,24(1),25,27-nona­ene

CROSSMARK_Color_square_no_text.svg
T. Thanh Van Tran,a* Le Tuan Anh,a Hung Huy Nguyen,a Hong Hieu Truongb and Anatoly T. Soldatenkovc

aFaculty of Chemistry, University of Science, Vietnam National University, 19 Le Thanh Tong, Hanoi, Vietnam, bInstitute of Chemistry, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Hanoi, Vietnam, and cOrganic Chemistry Department, Peoples Friendship University of Russia, Miklukho-Maklaya St. 6, Moscow 117198, Russian Federation
*Correspondence e-mail: tvche@yahoo.com

Edited by H. Stoeckli-Evans, University of Neuchâtel, Switzerland (Received 6 April 2016; accepted 6 April 2016; online 12 April 2016)

The title compound, C30H29NO4, is a tetra­cyclic system containing a 4-aryl­pyridine fragment, two benzene rings and an aza-17-crown-5 ether moiety, in a bowl-like arrangement. The pyridine ring is inclined to the 4-methyl­phenyl ring by 26.64 (6)°, and by 57.43 (6) and 56.81 (6)° to the benzene rings. The benzene rings are inclined to one another by 88.32 (6)°. In the crystal, mol­ecules are linked by pairs of C—H⋯N hydrogen bonds, forming inversion dimers with an R22(14) ring motif. The dimers are linked via a number of C—H⋯π inter­actions, forming a three-dimensional architecture.

CCDC reference: 1472697

1. Chemical context

Over the last decades, there has been considerable inter­est in pyridino-fused aza­crown ethers owing to their great theoret­ical and practical potential (Bradshaw et al., 1993[Bradshaw, J. S., Krakowiak & Izatt, R. M. (1993). In Aza-Crown Macrocycles. New York: J. Wiley & Sons.]). Among them, pyridino­crownophanes containing a benzo subunit show high effectiveness as complexating ligands in metal-ion capture and separation (Pedersen, 1988[Pedersen, C. J. (1988). Angew. Chem. 100, 1053-1059.]). They are also of inter­est as phase-transfer catalysts, as membrane ion transporting vehicles (Gokel & Murillo, 1996[Gokel, G. W. & Murillo, O. (1996). Acc. Chem. Res. 29, 425-432.]), as active components useful in environmental chemistry (Bradshaw & Izatt, 1997[Bradshaw, J. S. & Izatt, R. M. (1997). Acc. Chem. Res. 30, 338-345.]), in design technology for the construction of organic sensors (Costero et al., 2005[Costero, A. M., Bañuls, M. J., Aurell, M. J., Ochando, L. E. & Doménech, A. J. (2005). Tetrahedron, 61, 10309-10320.]) and as nanosized on–off switches and other mol­ecular electronic devices (Natali & Giordani, 2012[Natali, M. & Giordani, S. (2012). Chem. Soc. Rev. 41, 4010-4029.]). It has also been shown that the family of pyridino­aza­crown compounds can possess anti­bacterial (An et al., 1998[An, H., Wang, T., Mohan, V., Griffey, R. H. & Cook, P. D. (1998). Tetrahedron, 54, 3999-4012.]) and anti­cancer properties (Artiemenko et al., 2002[Artiemenko, A. G., Kovdienko, N. A., Kuz'min, V. E., Kamalov, G. L., Lozitskaya, R. N., Fedchuk, A. S., Lozitsky, V. P., Dyachenko, N. S. & Nosach, L. N. (2002). Exp. Oncol. 24, 123-127.]; Le et al., 2015[Le, T. A., Truong, H. H., Thi, T. P. N., Thi, N. D., To, H. T., Thi, H. P. & Soldatenkov, A. T. (2015). Mendeleev Commun. 25, 224-225.]).

Recently, we have proposed a new efficient one-step Chichibabin method for the preparation of a series of pyridino­crownophanes incorporating a 14-crown-4 ether moiety (Le et al., 2014[Le, T. A., Truong, H. H., Nguyen, P. T. T., Pham, H. T., Kotsuba, V. E., Soldatenkov, A. T., Khrustalev, V. N. & Wodajo, A. T. (2014). Macroheterocycles, 7, 386-390.], 2015[Le, T. A., Truong, H. H., Thi, T. P. N., Thi, N. D., To, H. T., Thi, H. P. & Soldatenkov, A. T. (2015). Mendeleev Commun. 25, 224-225.]; Anh et al., 2008[Anh, L. T., Levov, A. N., Soldatenkov, A. T., Gruzdev, R. D. & Khieu, T. H. (2008). Russ. J. Org. Chem. 44, 462-464.]; Levov et al., 2008[Levov, A. N., Anh, L. T., Komatova, A. I., Strokina, V. M., Soldatenkov, A. T. & Khrustalev, V. N. (2008). Russ. J. Org. Chem. 44, 456-461.]). During the course of our attempts to develop the chemistry of these aza­crown systems and obtain macrocyclic ligands which include more extended macro-heterocycles, namely the 17-crown-5 ether moiety, we have studied the Chichibabin-type condensation of 1,8-bis­(2-acetyl­phen­oxy)-3,6-dioxa­octane with 4-methyl­benzaldehyde and ammonium acetate in acetic acid. This reaction (Fig. 1[link]) proceeds smoothly under heating of the multicomponent mixture to give the expected aza­crown with reasonable yield (30%). Herein, we report on the synthesis and crystal structure of this new aza­crown compound (I)[link].

[Scheme 1]
[Figure 1]
Figure 1
Chichibabin-type condensation of 1,8-bis­(2-acetyl­phen­oxy)-3,6-dioxa­octane with 4-methyl­benzaldehyde and ammonium acetate to produce the title compound (I)[link].

2. Structural commentary

The mol­ecule of the title compound, (I)[link], is a tetra­cyclic system containing a 4-aryl­pyridine fragment (rings A = N22/C17–C22 and B = C23–C28), two benzene rings (C = C11–C16 and D = C30–C35), and an aza-17-crown-5 ether moiety, and has a bowl-like arrangement (Fig. 2[link]). While the dihedral angles between the benzene rings and the pyridine ring are A/D = 56.81 (6)° and A/C = 57.43 (6)°, the dihedral angle between the 4-methyl­phenyl ring (B) and the pyridine ring (A) in the 4-aryl­pyridine fragment is only 26.64 (6)°. The distances from the center of the macrocycle cavity, defined as the centroid of atoms O1/O4/O7/O10/N22, to the individual atoms O1, O4, O7, O10 and N22 are 2.813 (2), 2.549 (2), 2.588 (2), 2.517 (2) and 2.825 (2) Å, respectively.

[Figure 2]
Figure 2
Mol­ecular structure of the title compound (I)[link], with the atom labelling. Displacement ellipsoids are drawn at the 50% probability level.

3. Supra­molecular features

In the crystal, mol­ecules are linked by pairs of C—H⋯N hydrogen bonds, forming inversion dimers with an R22(14) ring motif (Table 1[link] and Fig. 3[link]). The dimers are linked via a number of C—H⋯π inter­actions, forming a three-dimensional structure (Table 1[link]).

Table 1
Hydrogen-bond geometry (Å, °)

Cg1, Cg2, Cg3 and Cg4 are the centroids of rings A (N22/C17–C21), C (C11–C16), B (C23–C28) and D (C30–C35), respectively.
D—H⋯A D—H H⋯A D⋯A D—H⋯A
C9—H9A⋯N22i 0.99 2.55 3.4606 (15) 152
C3—H3B⋯Cg2ii 0.99 2.75 3.6182 (15) 146
C12—H12⋯Cg3iii 0.95 2.93 3.7281 (13) 142
C25—H25⋯Cg4iv 0.95 2.86 3.6987 (15) 148
C27—H27⋯Cg1v 0.95 2.99 3.7685 (14) 140
C34—H34⋯Cg2i 0.95 2.77 3.5912 (13) 146
Symmetry codes: (i) -x+1, -y+1, -z+1; (ii) [-x+{\script{3\over 2}}, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]; (iii) [-x+{\script{3\over 2}}, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]; (iv) [-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]; (v) [-x+{\script{1\over 2}}, y-{\script{1\over 2}}, -z+{\script{3\over 2}}].
[Figure 3]
Figure 3
A view along the a axis of the crystal packing of the title compound (I)[link]. The C—H⋯N hydrogen bonds are shown as dashed lines (see Table 1[link]).

4. Database survey

A search of the Cambridge Structural Database (CSD, Version 5.38, update February 2016; Groom et al., 2016[Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171-179.]) for the macrocyclic substructure S1, illustrated in Fig. 4[link], gave three hits, viz. 2,4,15,17,20-penta­methyl-6,7,9,10,12,13,20,21-octa­hydro-19H-dibenzo[k,p][1,4,7,10,14]tetra­oxaza­cyclohepta­decine (DORPOQ; Rungsimanon et al., 2008[Rungsimanon, T., Laobuthee, A., Miyata, M. & Chirachanchai, S. (2008). J. Incl Phenom. Macrocycl Chem. 62, 333-338.]), 25,27-dimethyl-8,11,14,17-tetra­oxa-28-aza­tetra­cyclo­(22.3.1.02,7.018,23)octa­cosa-2,4,6,18 (23),19,21-hexen-26-one (EFIJEV; Levov et al., 2008[Levov, A. N., Anh, L. T., Komatova, A. I., Strokina, V. M., Soldatenkov, A. T. & Khrustalev, V. N. (2008). Russ. J. Org. Chem. 44, 456-461.]), and 20-cyclo­hexyl-2,4,15,17-tetra­methyl-6,7,9,10,12,13,20,21-octa­hydro-19H-dibenzo[k,p][1,4,7,10,14]tetra­oxaza­cyclo­hepta­decine (KUFWIS; Chirachanchai et al., 2009[Chirachanchai, S., Rungsimanon, T., Phongtamrug, S., Miyata, M. & Laobuthee, A. (2009). Tetrahedron, 65, 5855-5861.]), also illustrated in Fig. 4[link]. The two benzene rings are inclined to one another by 50.41 (6)° in DORPOQ, 88.28 (9)° in EFIJEV and 74.3 (9)° in KUGWIS. The corresponding dihedral angle in the title compound [D/C = 88.32 (6)°] is similar to that observed in EFIJEV.

[Figure 4]
Figure 4
Database search substructure S1, and results.

5. Synthesis and crystallization

The synthesis of the title compound (I)[link], is illustrated in Fig. 1[link]. Ammonium acetate (10.0 g, 130 mmol) was added to a solution of 1,8-bis­(2-acetyl­phen­oxy)-3,6-dioxa­octane (0.50 g, 1.30 mmol) and p-methyl­benzaldehyde (0.155 g, 1.30 mmol) in acetic acid (10 ml). The reaction mixture was then refluxed for 45 min (monitored by TLC until disappearance of the starting diketone spot). At the end of the reaction, the reaction mixture was left to cool to room temperature, neutralized with Na2CO3 and extracted with ethyl acetate. The extract was purified by column chromatography on silica gel to give colourless crystals of the title compound (I)[link] [yield 0.18 g, 30%; m.p. 471–472 K]. IR (KBr), ν cm−1: C=Npyridine (1607), C=Caromatic (1545, 1514, 1492), C—O—C (1182, 1120, 1058, 1029). 1H NMR (CDCl3, 500 MHz, 300 K): d = 2.42 (s, 3H, CH3), 3.18 (s, 4H, Hether), 3.62 and 4.11 (both t, 4H each, Hether, J = 8 Hz each), 7.0–6.98 (d, 2H, Harom), 7.13–7.10 (m, 2H, Harom), 7.30–7.29 (d, 2H, Harom), 7.37–7.34 (m, 2H, Harom), 7.66–7.62 (m, 4H, Harom), 7.75 (s, 2H, H25, 27). ESI–MS: [M + H]+ = 468.2. Analysis calculated for C30H29NO4: C, 77.07; H, 6.25; N, 3.00. Found: C, 77.22; H, 6.05; N, 3.12.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2[link]. The H atoms were placed in calculated positions and refined as riding atoms: C—H = 0.95–0.99 Å with Uiso(H) = 1.5Ueq(C-meth­yl) and 1.2Ueq(C) for other H atoms.

Table 2
Experimental details

Crystal data
Chemical formula C30H29NO4
Mr 467.54
Crystal system, space group Monoclinic, P21/n
Temperature (K) 100
a, b, c (Å) 10.0819 (4), 10.4531 (4), 23.6016 (9)
β (°) 100.607 (1)
V (Å3) 2444.80 (16)
Z 4
Radiation type Mo Kα
μ (mm−1) 0.08
Crystal size (mm) 0.14 × 0.12 × 0.12
 
Data collection
Diffractometer D8 Quest Bruker CMOS
Absorption correction Multi-scan (SADABS; Bruker, 2014[Bruker (2014). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.])
Tmin, Tmax 0.695, 0.746
No. of measured, independent and observed [I > 2σ(I)] reflections 77012, 5825, 4706
Rint 0.043
(sin θ/λ)max (Å−1) 0.658
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.040, 0.099, 1.01
No. of reflections 5825
No. of parameters 317
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.31, −0.20
Computer programs: APEX2 and SAINT (Bruker, 2014[Bruker (2014). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]), SHELXT2014 (Sheldrick, 2015a[Sheldrick, G. M. (2015a). Acta Cryst. A71, 3-8.]), SHELXL2014 (Sheldrick, 2015b[Sheldrick, G. M. (2015b). Acta Cryst. C71, 3-8.]), 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.]), Mercury (Macrae et al., 2008[Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466-470.]) and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

Supporting information

CCDC reference: 1472697

Crystal structure: contains datablocks Global, I. DOI: 10.1107/S2056989016005752/su5294sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S2056989016005752/su5294Isup2.hkl

checkCIF report


Chemical context top

Over the last decades, there has been considerable inter­est in pyridino-fused aza­crown ethers owing to their great theoretical and practical potential (Bradshaw et al., 1993). Among them, pyridino­crownophanes containing a benzo subunit show high effectiveness as complexating ligands in metal-ion capture and separation (Pedersen, 1988). They are also of inter­est as phase-transfer catalysts, as membrane ion transporting vehicles (Gokel & Murillo, 1996), as active components useful in environmental chemistry (Bradshaw & Izatt, 1997), in design technology for the construction of organic sensors (Costero et al., 2005) and as nanosized on–off switches and other molecular electronic devices (Natali & Giordani, 2012). It has also been shown that the family of pyridino­aza­crown compounds can possess anti­bacterial (An et al., 1998) and anti­cancer properties (Artiemenko et al., 2002; Le et al., 2015).

Recently, we have proposed a new efficient one-step Chichibabin method for the preparation of a series of pyridino­crownophanes incorporating a 14-crown-4 ether moiety (Le et al., 2014, 2015; Anh et al., 2008; Levov et al., 2008). During the course of our attempts to develop the chemistry of these aza­crown systems and obtain macrocyclic ligands which include more extended macro-heterocycles, namely the 17-crown-5 ether moiety, we have studied the Chichibabin-type condensation of 1,8-bis­(2-acetyl­phen­oxy)-3,6-dioxao­ctane with 4-methyl­benzaldehyde and ammonium acetate in acetic acid. This reaction (Fig. 1) proceeds smoothly under heating of the multicomponent mixture to give the expected aza­crown with reasonable yield (30%). Herein, we report on the synthesis and crystal structure of this new aza­crown compound (I).

Structural commentary top

The molecule of the title compound, (I), comprises a fused tetra­cyclic system containing a 4-aryl­pyridine fragment (rings A = N22/C17–C22 and B = C23–C28), two benzene rings (C = C11–C16 and D = C30–C35), and an aza-17-crown-5 ether moiety, and has a bowl-like arrangement (Fig. 2). While the dihedral angles between the benzene rings and the pyridine ring are A/D = 56.81 (6)° and A/C = 57.43 (6)°, the dihedral angle between 4-methyl­phenyl ring (B) and and pyridine ring (A) in the 4-aryl­pyridine fragment is only 26.64 (6)°. The distances from the center of the macrocycle cavity, defined as the centroid of atoms O1/O4/O7/O10/N22, to the individual atoms O1, O4, O7, O10 and N22 are 2.813 (2), 2.549 (2), 2.588 (2), 2.517 (2) and 2.825 (2) Å, respectively.

Supra­molecular features top

In the crystal, molecules are linked by pairs of C—H···N hydrogen bonds, forming inversion dimers with an R22(14) ring motif (Table 1 and Fig. 3). The dimers are linked via a number of C—H···π inter­actions, forming a three-dimensional structure (Table 1).

Database survey top

\ A search of the Cambridge Structural Database (CSD, Version 5.38, update February 2016; Groom et al., 2016) for the macrocyclic substructure S1, illustrated in Fig. 4, gave three hits, viz. 2,4,15,17,20-penta­methyl-6,7,9,10,12,13,20,21-o­cta­hydro-19H-\ dibenzo[k,p][1,4,7,10,14]tetra­oxaza­cyclo­heptadecine (DORPOQ; Rungsimanon et al., 2008), 25,27-di­methyl-8,11,14,17-tetra­oxa-28-aza­tetra­cyclo­(22.3.1.02,7.018,23)\ o­cta­cosa-2,4,6,18 (23),19,21-hexen-26-one (EFIJEV; Levov et al., 2008), and 20-cyclo­hexyl-2,4,15,17-tetra­methyl-6,7,9,10,12,13,20,21-o­cta­hydro-\ 19H-dibenzo[k,p][1,4,7,10,14]tetra­oxaza­cyclo­heptadecine (KUFWIS; Chirachanchai et al., 2009), also illustrated in Fig. 4. The two benzene rings are inclined to one another by 50.41 (6)° in DORPOQ, 88.28 (9)° in EFIJEV and 74.3 (9)° in KUGWIS. The corresponding dihedral angle in the title compound [D/C = 88.32 (6)°] is similar to that observed in EFIJEV.

Synthesis and crystallization top

The synthesis of the title compound (I), is illustrated in Fig. 1. Ammonium acetate (10.0 g, 130 mmol) was added to a solution of 1,8-bis­(2-acetyl­phen­oxy)-3,6-dioxao­ctane (0.50 g, 1.30 mmol) and p-methyl­benzaldehyde (0.155 g, 1.30 mmol) in acetic acid (10 ml). The reaction mixture was then refluxed for 45 min (monitored by TLC until disappearance of the starting diketone spot). At the end of the reaction, the reaction mixture was left to cool to room temperature, neutralized with Na2CO3 and extracted with ethyl acetate. The extract was purified by column chromatography on silica gel to give colourless crystals of the title compound (I) [yield 0.18 g, 30%; m.p. 471–472 K]. IR (KBr), ν cm-1: C═ Npyridine (1607), C═Caromatic (1545, 1514, 1492), C—O—C (1182, 1120, 1058, 1029). 1H NMR (CDCl3 , 500 MHz, 300 K): d = 2.42 (s, 3H, CH3), 3.18 (s, 4H, Hether), 3.62 and 4.11 (both t, 4H each, Hether, J = 8 Hz each), 7.0–6.98 (d, 2H, Harom), 7.13–7.10 (m, 2H, Harom), 7.30–7.29 (d, 2H, Harom), 7.37–7.34 (m, 2H, Harom), 7.66–7.62 (m, 4H, Harom), 7.75 (s, 2H, H25, 27). ESI–MS: [M + H]+ = 468.2. Analysis calculated for C30H29NO4 : C, 77.07; H, 6.25; N, 3.00. Found: C, 77.22; H, 6.05; N, 3.12.

Refinement top

Crystal data, data collection and structure refinement details are summarized in Table 2. The H atoms were placed in calculated positions and refined as riding atoms: C—H = 0.95–0.99 Å with Uiso(H) = 1.5Ueq(C-methyl) and 1.2Ueq(C) for other H atoms.

Structure description top

Over the last decades, there has been considerable inter­est in pyridino-fused aza­crown ethers owing to their great theoretical and practical potential (Bradshaw et al., 1993). Among them, pyridino­crownophanes containing a benzo subunit show high effectiveness as complexating ligands in metal-ion capture and separation (Pedersen, 1988). They are also of inter­est as phase-transfer catalysts, as membrane ion transporting vehicles (Gokel & Murillo, 1996), as active components useful in environmental chemistry (Bradshaw & Izatt, 1997), in design technology for the construction of organic sensors (Costero et al., 2005) and as nanosized on–off switches and other molecular electronic devices (Natali & Giordani, 2012). It has also been shown that the family of pyridino­aza­crown compounds can possess anti­bacterial (An et al., 1998) and anti­cancer properties (Artiemenko et al., 2002; Le et al., 2015).

Recently, we have proposed a new efficient one-step Chichibabin method for the preparation of a series of pyridino­crownophanes incorporating a 14-crown-4 ether moiety (Le et al., 2014, 2015; Anh et al., 2008; Levov et al., 2008). During the course of our attempts to develop the chemistry of these aza­crown systems and obtain macrocyclic ligands which include more extended macro-heterocycles, namely the 17-crown-5 ether moiety, we have studied the Chichibabin-type condensation of 1,8-bis­(2-acetyl­phen­oxy)-3,6-dioxao­ctane with 4-methyl­benzaldehyde and ammonium acetate in acetic acid. This reaction (Fig. 1) proceeds smoothly under heating of the multicomponent mixture to give the expected aza­crown with reasonable yield (30%). Herein, we report on the synthesis and crystal structure of this new aza­crown compound (I).

The molecule of the title compound, (I), comprises a fused tetra­cyclic system containing a 4-aryl­pyridine fragment (rings A = N22/C17–C22 and B = C23–C28), two benzene rings (C = C11–C16 and D = C30–C35), and an aza-17-crown-5 ether moiety, and has a bowl-like arrangement (Fig. 2). While the dihedral angles between the benzene rings and the pyridine ring are A/D = 56.81 (6)° and A/C = 57.43 (6)°, the dihedral angle between 4-methyl­phenyl ring (B) and and pyridine ring (A) in the 4-aryl­pyridine fragment is only 26.64 (6)°. The distances from the center of the macrocycle cavity, defined as the centroid of atoms O1/O4/O7/O10/N22, to the individual atoms O1, O4, O7, O10 and N22 are 2.813 (2), 2.549 (2), 2.588 (2), 2.517 (2) and 2.825 (2) Å, respectively.

In the crystal, molecules are linked by pairs of C—H···N hydrogen bonds, forming inversion dimers with an R22(14) ring motif (Table 1 and Fig. 3). The dimers are linked via a number of C—H···π inter­actions, forming a three-dimensional structure (Table 1).

\ A search of the Cambridge Structural Database (CSD, Version 5.38, update February 2016; Groom et al., 2016) for the macrocyclic substructure S1, illustrated in Fig. 4, gave three hits, viz. 2,4,15,17,20-penta­methyl-6,7,9,10,12,13,20,21-o­cta­hydro-19H-\ dibenzo[k,p][1,4,7,10,14]tetra­oxaza­cyclo­heptadecine (DORPOQ; Rungsimanon et al., 2008), 25,27-di­methyl-8,11,14,17-tetra­oxa-28-aza­tetra­cyclo­(22.3.1.02,7.018,23)\ o­cta­cosa-2,4,6,18 (23),19,21-hexen-26-one (EFIJEV; Levov et al., 2008), and 20-cyclo­hexyl-2,4,15,17-tetra­methyl-6,7,9,10,12,13,20,21-o­cta­hydro-\ 19H-dibenzo[k,p][1,4,7,10,14]tetra­oxaza­cyclo­heptadecine (KUFWIS; Chirachanchai et al., 2009), also illustrated in Fig. 4. The two benzene rings are inclined to one another by 50.41 (6)° in DORPOQ, 88.28 (9)° in EFIJEV and 74.3 (9)° in KUGWIS. The corresponding dihedral angle in the title compound [D/C = 88.32 (6)°] is similar to that observed in EFIJEV.

Synthesis and crystallization top

The synthesis of the title compound (I), is illustrated in Fig. 1. Ammonium acetate (10.0 g, 130 mmol) was added to a solution of 1,8-bis­(2-acetyl­phen­oxy)-3,6-dioxao­ctane (0.50 g, 1.30 mmol) and p-methyl­benzaldehyde (0.155 g, 1.30 mmol) in acetic acid (10 ml). The reaction mixture was then refluxed for 45 min (monitored by TLC until disappearance of the starting diketone spot). At the end of the reaction, the reaction mixture was left to cool to room temperature, neutralized with Na2CO3 and extracted with ethyl acetate. The extract was purified by column chromatography on silica gel to give colourless crystals of the title compound (I) [yield 0.18 g, 30%; m.p. 471–472 K]. IR (KBr), ν cm-1: C═ Npyridine (1607), C═Caromatic (1545, 1514, 1492), C—O—C (1182, 1120, 1058, 1029). 1H NMR (CDCl3 , 500 MHz, 300 K): d = 2.42 (s, 3H, CH3), 3.18 (s, 4H, Hether), 3.62 and 4.11 (both t, 4H each, Hether, J = 8 Hz each), 7.0–6.98 (d, 2H, Harom), 7.13–7.10 (m, 2H, Harom), 7.30–7.29 (d, 2H, Harom), 7.37–7.34 (m, 2H, Harom), 7.66–7.62 (m, 4H, Harom), 7.75 (s, 2H, H25, 27). ESI–MS: [M + H]+ = 468.2. Analysis calculated for C30H29NO4 : C, 77.07; H, 6.25; N, 3.00. Found: C, 77.22; H, 6.05; N, 3.12.

Refinement details top

Crystal data, data collection and structure refinement details are summarized in Table 2. The H atoms were placed in calculated positions and refined as riding atoms: C—H = 0.95–0.99 Å with Uiso(H) = 1.5Ueq(C-methyl) and 1.2Ueq(C) for other H atoms.

Computing details top

Data collection: APEX2 (Bruker, 2014); cell refinement: SAINT (Bruker, 2014); data reduction: SAINT (Bruker, 2014); program(s) used to solve structure: SHELXT2014 (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015b); molecular graphics: OLEX2 (Dolomanov et al., 2009) and Mercury (Macrae et al., 2008); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. Chichibabin-type condensation of 1,8-bis(2-acetylphenoxy)-3,6-dioxaoctane with 4-methylbenzaldehyde and ammonium acetate to produce the title compound (I).
[Figure 2] Fig. 2. Molecular structure of the title compound (I), with the atom labelling. Displacement ellipsoids are drawn at the 50% probability level.
[Figure 3] Fig. 3. A view along the a axis of the crystal packing of the title compound (I). The C—H···N hydrogen bonds are shown as dashed lines (see Table 1).
[Figure 4] Fig. 4. Database search substructure S1, and results.
26-(4-Methylphenyl)-8,11,14,17-tetraoxa-28-azatetracyclo[22.3.1.02,7.018,23]hexacosa-2,4,6,18 (23),19,21,24 (1),25,27-nonaene top
Crystal data top
C30H29NO4F(000) = 992
Mr = 467.54Dx = 1.270 Mg m−3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
a = 10.0819 (4) ÅCell parameters from 9281 reflections
b = 10.4531 (4) Åθ = 2.9–28.3°
c = 23.6016 (9) ŵ = 0.08 mm−1
β = 100.607 (1)°T = 100 K
V = 2444.80 (16) Å3Block, colourless
Z = 40.14 × 0.12 × 0.12 mm
Data collection top
D8 Quest Bruker CMOS
diffractometer		4706 reflections with I > 2σ(I)
Detector resolution: 0.5 pixels mm-1Rint = 0.043
ω and φ scansθmax = 27.9°, θmin = 2.8°
Absorption correction: multi-scan
(SADABS; Bruker, 2014)		h = −13→13
Tmin = 0.695, Tmax = 0.746k = −13→13
77012 measured reflectionsl = −31→30
5825 independent reflections
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.040H-atom parameters constrained
wR(F2) = 0.099 w = 1/[σ2(Fo2) + (0.0422P)2 + 1.1744P]
where P = (Fo2 + 2Fc2)/3
S = 1.01(Δ/σ)max = 0.001
5825 reflectionsΔρmax = 0.31 e Å−3
317 parametersΔρmin = −0.19 e Å−3
Crystal data top
C30H29NO4V = 2444.80 (16) Å3
Mr = 467.54Z = 4
Monoclinic, P21/nMo Kα radiation
a = 10.0819 (4) ŵ = 0.08 mm−1
b = 10.4531 (4) ÅT = 100 K
c = 23.6016 (9) Å0.14 × 0.12 × 0.12 mm
β = 100.607 (1)°
Data collection top
D8 Quest Bruker CMOS
diffractometer		5825 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2014)		4706 reflections with I > 2σ(I)
Tmin = 0.695, Tmax = 0.746Rint = 0.043
77012 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0400 restraints
wR(F2) = 0.099H-atom parameters constrained
S = 1.01Δρmax = 0.31 e Å−3
5825 reflectionsΔρmin = −0.19 e Å−3
317 parameters
Special details top

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

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.76598 (8)0.67651 (8)0.70887 (4)0.02073 (19)
C20.90811 (12)0.64977 (12)0.71765 (6)0.0236 (3)
H2A0.95850.71230.74500.028*
H2B0.94070.65610.68070.028*
C30.93002 (13)0.51576 (13)0.74174 (6)0.0260 (3)
H3A1.02610.50600.76000.031*
H3B0.87520.50420.77210.031*
O40.89565 (10)0.41796 (9)0.69952 (4)0.0283 (2)
C50.75342 (13)0.40022 (13)0.68115 (6)0.0254 (3)
H5A0.71480.47350.65700.030*
H5B0.70880.39560.71510.030*
C60.72925 (15)0.27780 (13)0.64690 (6)0.0276 (3)
H6A0.77220.20650.67120.033*
H6B0.63100.26100.63820.033*
O70.77874 (10)0.27738 (9)0.59417 (4)0.0294 (2)
C80.71355 (13)0.36342 (13)0.55114 (5)0.0240 (3)
H8A0.76740.36830.52010.029*
H8B0.71370.44970.56850.029*
C90.57024 (12)0.32947 (12)0.52436 (5)0.0191 (2)
H9A0.54620.36790.48550.023*
H9B0.56020.23550.52060.023*
O100.48389 (8)0.37838 (9)0.56118 (4)0.0226 (2)
C110.71707 (12)0.77257 (11)0.67121 (5)0.0169 (2)
C120.79826 (12)0.86832 (12)0.65433 (5)0.0202 (2)
H120.89240.86940.66940.024*
C130.74163 (13)0.96191 (12)0.61564 (5)0.0216 (3)
H130.79731.02670.60410.026*
C140.60453 (13)0.96142 (12)0.59371 (5)0.0223 (3)
H140.56561.02610.56750.027*
C150.52418 (12)0.86528 (12)0.61036 (5)0.0200 (2)
H150.43030.86460.59490.024*
C160.57788 (12)0.77018 (11)0.64904 (5)0.0167 (2)
C170.48787 (11)0.66625 (11)0.66367 (5)0.0164 (2)
C180.47440 (12)0.64112 (11)0.72038 (5)0.0177 (2)
H180.52570.68820.75130.021*
C190.38500 (11)0.54616 (11)0.73144 (5)0.0173 (2)
C200.31490 (12)0.47876 (11)0.68404 (5)0.0182 (2)
H200.25260.41370.68950.022*
C210.33672 (11)0.50726 (11)0.62894 (5)0.0170 (2)
N220.41964 (10)0.60176 (9)0.61821 (4)0.0168 (2)
C230.36716 (11)0.51592 (12)0.79121 (5)0.0182 (2)
C240.39161 (13)0.60818 (13)0.83481 (5)0.0233 (3)
H240.41820.69200.82610.028*
C250.37740 (14)0.57841 (14)0.89078 (5)0.0264 (3)
H250.39300.64280.91960.032*
C260.34073 (12)0.45582 (14)0.90541 (5)0.0243 (3)
C270.31736 (12)0.36405 (13)0.86220 (6)0.0231 (3)
H270.29300.27970.87130.028*
C280.32895 (12)0.39334 (12)0.80585 (5)0.0207 (3)
H280.31070.32930.77690.025*
C290.32647 (14)0.42573 (16)0.96669 (6)0.0331 (3)
H29A0.41590.42460.99140.050*
H29B0.28370.34180.96790.050*
H29C0.27050.49130.98040.050*
C300.26916 (12)0.43182 (11)0.57809 (5)0.0177 (2)
C310.12989 (13)0.42073 (12)0.56426 (6)0.0241 (3)
H310.07550.45970.58830.029*
C320.06873 (13)0.35301 (13)0.51548 (6)0.0279 (3)
H32−0.02680.34690.50620.034*
C330.14684 (13)0.29501 (12)0.48079 (6)0.0240 (3)
H330.10470.25020.44730.029*
C340.28687 (13)0.30147 (12)0.49435 (5)0.0208 (3)
H340.34040.26000.47070.025*
C350.34786 (12)0.36931 (11)0.54301 (5)0.0180 (2)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0174 (4)0.0189 (4)0.0258 (4)−0.0004 (3)0.0037 (3)0.0035 (3)
C20.0177 (6)0.0225 (6)0.0299 (7)−0.0001 (5)0.0023 (5)0.0013 (5)
C30.0239 (6)0.0238 (7)0.0276 (7)0.0010 (5)−0.0024 (5)0.0017 (5)
O40.0277 (5)0.0221 (5)0.0332 (5)0.0041 (4)0.0006 (4)−0.0031 (4)
C50.0277 (7)0.0229 (6)0.0242 (6)0.0009 (5)0.0012 (5)−0.0007 (5)
C60.0370 (8)0.0201 (6)0.0235 (6)0.0021 (6)−0.0002 (5)0.0027 (5)
O70.0303 (5)0.0283 (5)0.0280 (5)0.0122 (4)0.0016 (4)−0.0012 (4)
C80.0213 (6)0.0281 (7)0.0244 (6)0.0036 (5)0.0092 (5)0.0040 (5)
C90.0227 (6)0.0193 (6)0.0174 (5)0.0030 (5)0.0090 (5)0.0013 (5)
O100.0162 (4)0.0311 (5)0.0214 (4)0.0001 (4)0.0057 (3)−0.0089 (4)
C110.0196 (6)0.0140 (5)0.0176 (5)−0.0007 (4)0.0050 (4)−0.0024 (4)
C120.0189 (6)0.0180 (6)0.0247 (6)−0.0031 (5)0.0067 (5)−0.0046 (5)
C130.0281 (6)0.0150 (6)0.0245 (6)−0.0049 (5)0.0120 (5)−0.0021 (5)
C140.0288 (7)0.0174 (6)0.0216 (6)0.0010 (5)0.0071 (5)0.0030 (5)
C150.0198 (6)0.0202 (6)0.0205 (6)−0.0005 (5)0.0046 (5)−0.0015 (5)
C160.0195 (6)0.0156 (5)0.0167 (5)−0.0021 (4)0.0075 (4)−0.0029 (4)
C170.0148 (5)0.0156 (5)0.0195 (6)0.0008 (4)0.0052 (4)−0.0008 (4)
C180.0173 (5)0.0180 (6)0.0179 (5)−0.0012 (4)0.0040 (4)−0.0019 (4)
C190.0153 (5)0.0181 (6)0.0195 (6)0.0017 (4)0.0060 (4)−0.0002 (4)
C200.0163 (5)0.0172 (6)0.0229 (6)−0.0023 (4)0.0078 (4)−0.0012 (5)
C210.0146 (5)0.0165 (6)0.0207 (6)0.0006 (4)0.0055 (4)−0.0019 (4)
N220.0159 (5)0.0166 (5)0.0188 (5)−0.0002 (4)0.0055 (4)−0.0014 (4)
C230.0141 (5)0.0219 (6)0.0191 (6)0.0009 (4)0.0047 (4)0.0020 (5)
C240.0280 (7)0.0218 (6)0.0208 (6)−0.0014 (5)0.0064 (5)0.0016 (5)
C250.0297 (7)0.0312 (7)0.0186 (6)−0.0020 (6)0.0050 (5)−0.0008 (5)
C260.0160 (6)0.0366 (7)0.0204 (6)0.0007 (5)0.0037 (5)0.0076 (5)
C270.0167 (6)0.0256 (6)0.0282 (7)−0.0015 (5)0.0069 (5)0.0082 (5)
C280.0158 (6)0.0223 (6)0.0252 (6)−0.0015 (5)0.0063 (5)0.0006 (5)
C290.0280 (7)0.0489 (9)0.0219 (7)−0.0044 (6)0.0034 (5)0.0117 (6)
C300.0188 (6)0.0154 (5)0.0193 (6)−0.0021 (4)0.0047 (4)−0.0008 (4)
C310.0199 (6)0.0240 (6)0.0298 (7)−0.0015 (5)0.0083 (5)−0.0059 (5)
C320.0171 (6)0.0302 (7)0.0351 (7)−0.0035 (5)0.0013 (5)−0.0064 (6)
C330.0257 (6)0.0225 (6)0.0223 (6)−0.0050 (5)0.0004 (5)−0.0042 (5)
C340.0247 (6)0.0195 (6)0.0190 (6)−0.0009 (5)0.0061 (5)−0.0020 (5)
C350.0180 (6)0.0183 (6)0.0183 (6)−0.0019 (4)0.0049 (4)0.0008 (4)
Geometric parameters (Å, º) top
O1—C21.4370 (15)C18—C191.3973 (16)
O1—C111.3712 (14)C19—C201.3987 (17)
C2—C31.5126 (18)C19—C231.4886 (16)
C3—O41.4251 (16)C20—C211.3905 (16)
O4—C51.4317 (16)C21—N221.3479 (15)
C5—C61.5093 (18)C21—C301.4917 (16)
C6—O71.4236 (17)C23—C241.3987 (17)
O7—C81.4235 (15)C23—C281.3995 (17)
C8—C91.5089 (17)C24—C251.3900 (17)
C9—O101.4329 (14)C25—C261.3946 (19)
O10—C351.3628 (14)C26—C271.3883 (19)
C11—C121.3966 (16)C26—C291.5125 (17)
C11—C161.4047 (16)C27—C281.3905 (17)
C12—C131.3874 (18)C30—C311.3867 (17)
C13—C141.3839 (18)C30—C351.4084 (16)
C14—C151.3921 (17)C31—C321.3947 (18)
C15—C161.3901 (17)C32—C331.3768 (19)
C16—C171.4962 (16)C33—C341.3906 (18)
C17—C181.3948 (16)C34—C351.3928 (17)
C17—N221.3444 (15)
C11—O1—C2117.77 (9)C20—C19—C23121.31 (11)
O1—C2—C3107.88 (10)C21—C20—C19119.77 (11)
O4—C3—C2113.69 (11)C20—C21—C30120.79 (10)
C3—O4—C5113.93 (10)N22—C21—C20122.89 (11)
O4—C5—C6109.02 (11)N22—C21—C30116.32 (10)
O7—C6—C5115.01 (11)C17—N22—C21117.48 (10)
C8—O7—C6115.57 (10)C24—C23—C19121.01 (11)
O7—C8—C9115.53 (11)C24—C23—C28117.96 (11)
O10—C9—C8107.68 (10)C28—C23—C19121.01 (11)
C35—O10—C9118.22 (9)C25—C24—C23120.65 (12)
O1—C11—C12123.37 (11)C24—C25—C26121.29 (12)
O1—C11—C16116.35 (10)C25—C26—C29120.26 (13)
C12—C11—C16120.28 (11)C27—C26—C25118.03 (12)
C13—C12—C11120.08 (11)C27—C26—C29121.71 (13)
C14—C13—C12120.35 (11)C26—C27—C28121.18 (12)
C13—C14—C15119.34 (11)C27—C28—C23120.87 (12)
C16—C15—C14121.68 (11)C31—C30—C21121.75 (11)
C11—C16—C17122.26 (10)C31—C30—C35118.58 (11)
C15—C16—C11118.26 (11)C35—C30—C21119.67 (10)
C15—C16—C17119.43 (11)C30—C31—C32120.76 (12)
C18—C17—C16121.91 (10)C33—C32—C31120.00 (12)
N22—C17—C16115.01 (10)C32—C33—C34120.62 (12)
N22—C17—C18123.06 (11)C33—C34—C35119.34 (11)
C17—C18—C19119.54 (11)O10—C35—C30115.21 (10)
C18—C19—C20117.18 (11)O10—C35—C34124.11 (11)
C18—C19—C23121.50 (11)C34—C35—C30120.66 (11)
Hydrogen-bond geometry (Å, º) top
Cg1, Cg2, Cg3 and Cg4 are the centroids of rings A (N22/C17–C21), C (C11–C16), B (C23–C28) and D (C30–C35), respectively.
D—H···AD—HH···AD···AD—H···A
C9—H9A···N22i0.992.553.4606 (15)152
C3—H3B···Cg2ii0.992.753.6182 (15)146
C12—H12···Cg3iii0.952.933.7281 (13)142
C25—H25···Cg4iv0.952.863.6987 (15)148
C27—H27···Cg1v0.952.993.7685 (14)140
C34—H34···Cg2i0.952.773.5912 (13)146
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+3/2, y−1/2, −z+3/2; (iii) −x+3/2, y+1/2, −z+3/2; (iv) −x+1/2, y+1/2, −z+3/2; (v) −x+1/2, y−1/2, −z+3/2.
Hydrogen-bond geometry (Å, º) top
Cg1, Cg2, Cg3 and Cg4 are the centroids of rings A (N22/C17–C21), C (C11–C16), B (C23–C28) and D (C30–C35), respectively.
D—H···AD—HH···AD···AD—H···A
C9—H9A···N22i0.992.553.4606 (15)152
C3—H3B···Cg2ii0.992.753.6182 (15)146
C12—H12···Cg3iii0.952.933.7281 (13)142
C25—H25···Cg4iv0.952.863.6987 (15)148
C27—H27···Cg1v0.952.993.7685 (14)140
C34—H34···Cg2i0.952.773.5912 (13)146
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+3/2, y−1/2, −z+3/2; (iii) −x+3/2, y+1/2, −z+3/2; (iv) −x+1/2, y+1/2, −z+3/2; (v) −x+1/2, y−1/2, −z+3/2.

Experimental details

Crystal data
Chemical formulaC30H29NO4
Mr467.54
Crystal system, space groupMonoclinic, P21/n
Temperature (K)100
a, b, c (Å)10.0819 (4), 10.4531 (4), 23.6016 (9)
β (°) 100.607 (1)
V (Å3)2444.80 (16)
Z4
Radiation typeMo Kα
µ (mm−1)0.08
Crystal size (mm)0.14 × 0.12 × 0.12
Data collection
DiffractometerD8 Quest Bruker CMOS
Absorption correctionMulti-scan
(SADABS; Bruker, 2014)
Tmin, Tmax0.695, 0.746
No. of measured, independent and
observed [I > 2σ(I)] reflections		77012, 5825, 4706
Rint0.043
(sin θ/λ)max (Å−1)0.658
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.040, 0.099, 1.01
No. of reflections5825
No. of parameters317
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å−3)0.31, −0.19

Computer programs: APEX2 (Bruker, 2014), SAINT (Bruker, 2014), SHELXT2014 (Sheldrick, 2015a), SHELXL2014 (Sheldrick, 2015b), OLEX2 (Dolomanov et al., 2009) and Mercury (Macrae et al., 2008), OLEX2 (Dolomanov et al., 2009) and PLATON (Spek, 2009).

 

Acknowledgements

This research is funded by the Vietnam National University, Hanoi (VNU), under project number QG.16.05.

References

First citationAn, H., Wang, T., Mohan, V., Griffey, R. H. & Cook, P. D. (1998). Tetrahedron, 54, 3999–4012.  Web of Science CrossRef CAS Google Scholar
 First citationAnh, L. T., Levov, A. N., Soldatenkov, A. T., Gruzdev, R. D. & Khieu, T. H. (2008). Russ. J. Org. Chem. 44, 462–464.  Google Scholar
 First citationArtiemenko, A. G., Kovdienko, N. A., Kuz'min, V. E., Kamalov, G. L., Lozitskaya, R. N., Fedchuk, A. S., Lozitsky, V. P., Dyachenko, N. S. & Nosach, L. N. (2002). Exp. Oncol. 24, 123–127.  Google Scholar
 First citationBradshaw, J. S. & Izatt, R. M. (1997). Acc. Chem. Res. 30, 338–345.  CrossRef CAS Web of Science Google Scholar
 First citationBradshaw, J. S., Krakowiak & Izatt, R. M. (1993). In Aza-Crown Macrocycles. New York: J. Wiley & Sons.  Google Scholar
 First citationBruker (2014). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
 First citationChirachanchai, S., Rungsimanon, T., Phongtamrug, S., Miyata, M. & Laobuthee, A. (2009). Tetrahedron, 65, 5855–5861.  Web of Science CSD CrossRef CAS Google Scholar
 First citationCostero, A. M., Bañuls, M. J., Aurell, M. J., Ochando, L. E. & Doménech, A. J. (2005). Tetrahedron, 61, 10309–10320.  Web of Science CSD CrossRef CAS Google Scholar
 First citationDolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339–341.  Web of Science CrossRef CAS IUCr Journals Google Scholar
 First citationGokel, G. W. & Murillo, O. (1996). Acc. Chem. Res. 29, 425–432.  CrossRef CAS Web of Science Google Scholar
 First citationGroom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171–179.  CSD CrossRef IUCr Journals Google Scholar
 First citationLe, T. A., Truong, H. H., Nguyen, P. T. T., Pham, H. T., Kotsuba, V. E., Soldatenkov, A. T., Khrustalev, V. N. & Wodajo, A. T. (2014). Macroheterocycles, 7, 386–390.  Web of Science CrossRef Google Scholar
 First citationLe, T. A., Truong, H. H., Thi, T. P. N., Thi, N. D., To, H. T., Thi, H. P. & Soldatenkov, A. T. (2015). Mendeleev Commun. 25, 224–225.  Web of Science CrossRef CAS Google Scholar
 First citationLevov, A. N., Anh, L. T., Komatova, A. I., Strokina, V. M., Soldatenkov, A. T. & Khrustalev, V. N. (2008). Russ. J. Org. Chem. 44, 456–461.  Web of Science CrossRef CAS Google Scholar
 First citationMacrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
 First citationNatali, M. & Giordani, S. (2012). Chem. Soc. Rev. 41, 4010–4029.  Web of Science CrossRef CAS PubMed Google Scholar
 First citationPedersen, C. J. (1988). Angew. Chem. 100, 1053–1059.  CrossRef CAS Google Scholar
 First citationRungsimanon, T., Laobuthee, A., Miyata, M. & Chirachanchai, S. (2008). J. Incl Phenom. Macrocycl Chem. 62, 333–338.  Web of Science CSD CrossRef CAS Google Scholar
 First citationSheldrick, G. M. (2015a). Acta Cryst. A71, 3–8.  Web of Science CrossRef IUCr Journals Google Scholar
 First citationSheldrick, G. M. (2015b). Acta Cryst. C71, 3–8.  Web of Science CrossRef IUCr Journals Google Scholar
 First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 72| Part 5| May 2016| Pages 663-666
doi:10.1107/S2056989016005752
Follow Acta Cryst. E
Sign up for e-alerts
E-alerts
Follow Acta Cryst. on Twitter
Twitter
Follow us on facebook
Facebook
Sign up for RSS feeds
RSS