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ISSN: 2056-9890

Crystal structures and Hirshfeld surface analyses of two new tetra­kis-substituted pyrazines and a degredation product

aInstitute of Chemistry, University of Neuchâtel, Av. de Bellvaux 15, CH-2000 Neuchâtel, Switzerland, and bInstitute of Physics, University of Neuchâtel, rue Emile-Argand 11, CH-2000 Neuchâtel, Switzerland
*Correspondence e-mail: helen.stoeckli-evans@unine.ch

Edited by C. Massera, Università di Parma, Italy (Received 27 January 2020; accepted 14 February 2020; online 18 February 2020)

The two new tetra­kis-substituted pyrazines, 1,1′,1′′,1′′′-(pyrazine-2,3,5,6-tetra­yl) tetra­kis­(N,N-di­methyl­methanamine), C16H32N6, (I) and N,N′,N′′,N′′′-[pyrazine-2,3,5,6-tetra­yltetra­kis­(methyl­ene)]tetra­kis­(N-methyl­aniline), C36H40N6, (II), both crystallize with half a mol­ecule in the asymmetric unit; the whole mol­ecules are generated by inversion symmetry. There are weak intra­molecular C—H⋯N hydrogen bonds present in both mol­ecules and in (II) the pendant N-methyl­aniline rings are linked by a C—H⋯π inter­action. The degredation product, N,N′-[(6-phenyl-6,7-di­hydro-5H-pyrrolo­[3,4-b]pyrazine-2,3-di­yl)bis(methyl­ene)]bis­(N-methyl­aniline), C28H29N5, (III), was obtained several times by reacting (II) with different metal salts. Here, the 6-phenyl ring is almost coplanar with the planar pyrrolo­[3,4-b]pyrazine unit (r.m.s. deviation = 0.029 Å), with a dihedral angle of 4.41 (10)° between them. The two N-meth­yl­aniline rings are inclined to the planar pyrrolo­[3,4-b]pyrazine unit by 88.26 (10) and 89.71 (10)°, and to each other by 72.56 (13)°. There are also weak intra­molecular C—H⋯N hydrogen bonds present involving the pyrazine ring and the two N-methyl­aniline groups. In the crystal of (I), there are no significant inter­molecular contacts present, while in (II) mol­ecules are linked by a pair of C—H⋯π inter­actions, forming chains along the c-axis direction. In the crystal of (III), mol­ecules are linked by two pairs of C—H⋯π inter­actions, forming inversion dimers, which in turn are linked by offset ππ inter­actions [inter­centroid distance = 3.8492 (19) Å], forming ribbons along the b-axis direction.

1. Chemical context

Tetra­kis-substituted pyrazines, which are potential bis-tridentate ligands, have been used in coordination chemistry since the 1980′s, to form not only mononuclear and binuclear complexes but also multi-dimensional coordination polymers. A search of the Cambridge Structural Database (CSD, Version 5.41, last update November 2019; Groom et al., 2016[Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171-179.]) reveals that the principal tetra­kis-substituted pyrazine ligands that have been used are 2,3,5,6-tetra­kis­(pyridin-2-yl)pyrazine, which was first synthesized by Goodwin & Lions (1959[Goodwin, H. A. & Lions, F. (1959). J. Am. Chem. Soc. 81, 6415-6422.]), and 2,3,5,6-pyrazine­tetra­carb­oxy­lic acid, which was first synthesized by Wolff at the end of the 19th century (Wolff, 1887[Wolff, L. (1887). Ber. Dtsch. Chem. Ges. 20, 425-433.], 1893[Wolff, L. (1893). Ber. Dtsch. Chem. Ges. 26, 721-725.]). Since then the coordination chemistry of only a small number of tetra­kis-substituted pyrazines has been studied, for example tetra­kis­(amino­meth­yl)pyrazine (Ferigo et al., 1994[Ferigo, M., Bonhôte, P., Marty, W. & Stoeckli-Evans, H. (1994). J. Chem. Soc. Dalton Trans. pp. 1549-1554.]) and, more recently, the new ligand 2,3,5,6-tetra­kis­(4-carb­oxy­phen­yl) pyrazine, which has been shown to be extremely successful in forming metal–organic frameworks (Jiang et al., 2017[Jiang, Y., Sun, L., Du, J., Liu, Y., Shi, H., Liang, Z. & Li, J. (2017). Cryst. Growth Des. 17, 2090-2096.]; Wang et al., 2019[Wang, L., Zou, R., Guo, W., Gao, S., Meng, W., Yang, J., Chen, X. & Zou, R. (2019). Inorg. Chem. Commun. 104, 78-82.]).

[Scheme 1]

In our search for new tetra­kis-substituted pyrazine ligands (Tesouro Vallina, 2001[Tesouro Vallina, A. (2001). PhD Thesis. University of Neuchâtel, Switzerland.]), viz. potential bis-tridentate ligands, the title compounds, 1,1′,1′′,1′′′-(pyrazine-2,3,5,6-tetra­yl) tetra­kis­(N,N-di­methyl­methanamine) (I)[link] and N,N′,N′′,N′′′-[pyrazine-2,3,5,6-tetra­yltetra­kis­(methyl­ene)]tetra­kis­(N-methyl­aniline) (II)[link] were synthesized. During attempts to form transition-metal complexes of (II)[link], the degradation product, N,N′-[(6-phenyl-6,7-di­hydro-5H-pyrrolo­[3,4-b]pyrazine-2,3-di­yl)bis­(methyl­ene)]bis­(N-methyl­aniline) (III)[link] was often formed. Herein, we describe their mol­ecular and crystal structures, together with the Hirshfeld surface analysis of their crystal packing.

2. Structural commentary

The mol­ecular structure of compound (I)[link] is illustrated in Fig. 1[link]. The mol­ecule possesses inversion symmetry with the pyrazine ring being located about a center of symmetry. The adjacent di­methyl­methanamine substituents, in positions 2,3 (and 5,6), are directed above and below the plane of the pyrazine ring. There is a short intra­molecular C3—H3A⋯N3i contact on either side of the mol­ecule [symmetry code: (i) −x, −y, −z 1 ], linking the two di­methyl­methanamine substituents (Fig. 1[link] and Table 1[link]).

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

D—H⋯A D—H H⋯A DA D—H⋯A
C3—H3A⋯N3i 0.97 2.62 3.261 (4) 124
Symmetry code: (i) -x, -y, -z+1.
[Figure 1]
Figure 1
A view of the mol­ecular structure of compound (I)[link], with atom labelling [symmetry code: (i) −x, −y, −z + 1]. Displacement ellipsoids are drawn at the 30% probability level. Intra­molecular C—H⋯N inter­actions (Table 1[link]) are shown as dashed lines.

The mol­ecular structure of compound (II)[link] is illustrated in Fig. 2[link]. This mol­ecule also possesses inversion symmetry with the pyrazine ring being located about a center of symmetry. Again the adjacent methyl­aniline substituents, in positions 2,3 (and 5,6), are directed above and below the plane of the pyrazine ring. Rings C4–C9 and C12–C17 are inclined to the pyrazine ring by 63.62 (10) and 86.83 (10)°, respectively, and to each other by 78.28 (11)°. There are short intra­molecular C5—H5⋯N1 contacts on either side of the mol­ecule involving a methyl­aniline ring and the adjacent pyrazine N atom, and the methyl­aniline substituents in positions 2,6 (and 3,5) are linked by an intra­molecular C6—H6⋯π inter­action (Fig. 2[link] and Table 2[link]).

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

Cg2 and Cg3 are the centroids of rings C4–C9 and C12–C17, respectively.

D—H⋯A D—H H⋯A DA D—H⋯A
C5—H5⋯N1 0.93 2.50 3.331 (3) 149
C6—H6⋯Cg3 0.93 2.99 3.804 (3) 147
C3—H3A⋯Cg2i 0.97 2.83 3.561 (2) 133
Symmetry code: (i) -x+1, -y+1, -z+1.
[Figure 2]
Figure 2
A view of the mol­ecular structure of compound (II)[link], with atom labelling [symmetry code: (i) −x + 1, −y + 1, −z + 2]. Displacement ellipsoids are drawn at the 30% probability level. Intra­molecular C—H⋯N inter­actions (Table 2[link]) are shown as dashed lines and the intra­molecular C—H⋯π inter­actions (Table 2[link]) as red dashed arrows.

The mol­ecular structure of compound (III)[link] is illustrated in Fig. 3[link]. One side of the mol­ecule has been transformed into a pyrrolo unit fused to the pyrazine ring. The 6-phenyl ring (C7–C12) is almost coplanar with the planar pyrrolo­[3,4-b]pyrazine unit (N1–N3/C1–C6; r.m.s. deviation = 0.029 Å), forming a dihedral angle of 4.41 (10)°. On the other side of the mol­ecule, the two adjacent N-methyl­aniline rings (C14–C19 and C22–C27) are inclined to the planar pyrrolo­[3,4-b]pyrazine unit by 88.26 (10) and 89.71 (10)°, and to each other by 72.56 (13)°. There are also weak intra­molecular C—H⋯N hydrogen bonds present involving the pyrazine ring and the two N-methyl­aniline groups (Fig. 3[link] and Table 3[link]).

Table 3
Hydrogen-bond geometry (Å, °) for (III)[link]

Cg2 and Cg3 are the centroids of rings N1/N2/C1–C4 and C7–C12, respectively.

D—H⋯A D—H H⋯A DA D—H⋯A
C15—H15⋯N4 0.93 2.61 3.542 (3) 175
C28—H28B⋯N2 0.96 2.59 3.323 (3) 133
C6—H6BCg2i 0.97 2.82 3.601 (2) 138
C23—H23⋯Cg3i 0.93 2.97 3.881 (3) 168
Symmetry code: (i) -x+1, -y+2, -z.
[Figure 3]
Figure 3
A view of the mol­ecular structure of compound (III)[link], with atom labelling. Displacement ellipsoids are drawn at the 30% probability level. Intra­molecular C—H⋯N inter­actions (Table 3[link]) are shown as dashed lines.

3. Supra­molecular features

In the crystal of (I)[link], there are no significant inter­molecular inter­actions present (Fig. 4[link]).

[Figure 4]
Figure 4
A view along the a axis of the crystal packing of compound (I)[link].

In the crystal of (II)[link], mol­ecules are linked by a pair of C—H⋯π inter­actions, forming chains that propagate along the [001] direction (Fig. 5[link] and Table 2[link]).

[Figure 5]
Figure 5
A view along the a axis of the crystal packing of compound (II)[link]. The C3—H3Aπ inter­actions (Table 2[link]) are shown as blue dashed arrows, and for clarity, only H atom H3A (blue) has been included.

In the crystal of (III)[link], mol­ecules are linked by two pairs of C—H⋯π inter­actions, forming inversion dimers. Offset ππ inter­actions link the dimers to form ribbons propagating along the [010] direction; see Fig. 6[link] and Table 3[link]. The offset ππ inter­action, Cg3⋯Cg6ii, where Cg3 and Cg6 are, respectively, the centroids of the phenyl ring (C7–C12) and the pyrrolo[3,4-b]pyrazine ring system, has a centroid–centroid distance of 3.8492 (14) Å, α = 4.41 (10)°, inter­planar distances of 3.6495 (14) and 3.5490 (7) Å, with an offset of 1.49 Å [symmetry code: (ii) −x + 1, −y + 1, −z].

[Figure 6]
Figure 6
A view along the a axis of the crystal packing of compound (III)[link]. The C—H⋯π inter­actions (Table 3[link]) are shown as blue and red dashed arrows. For clarity, only the H atoms H6B (blue) and H23 (red) have been included. The offset π-π- inter­actions are shown as orange dashed double arrows.

4. Hirshfeld surface analysis and two-dimensional fingerprint plots

The Hirshfeld surface analysis (Spackman & Jayatilaka, 2009[Spackman, M. A. & Jayatilaka, D. (2009). CrystEngComm, 11, 19-32.]) and the associated two-dimensional fingerprint plots (McKinnon et al., 2007[McKinnon, J. J., Jayatilaka, D. & Spackman, M. A. (2007). Chem. Commun. pp. 3814-3816.]) were performed with CrystalExplorer17 (Turner et al., 2017[Turner, M. J., McKinnon, J. J., Wolff, S. K., Grimwood, D. J., Spackman, P. R., Jayatilaka, D. & Spackman, M. A. (2017). CrystalExplorer17. University of Western Australia. http://hirshfeldsurface.net]).

The Hirshfeld surfaces are colour-mapped with the normalized contact distance, dnorm, from red (distances shorter than the sum of the van der Waals radii) through white to blue (distances longer than the sum of the van der Waals radii). The Hirshfeld surfaces (HS) of the title compounds, mapped over dnorm, are given in Fig. 7[link]. It is evident from Figs. 7[link]a and 7b that there are no contact distances shorter than the sum of the van der Waals radii in the crystals of either compounds (I)[link] or (II)[link]. For compound (III)[link] (Fig. 7[link]c), two small red spots indicate the presence of weak C⋯H contacts (see Table 3[link]).

[Figure 7]
Figure 7
(a) The Hirshfeld surface of compound (I)[link], mapped over dnorm in the colour range −0.7519 to 1.6997 a.u., (b) the Hirshfeld surface of compound (II)[link], mapped over dnorm in the colour range −0.7519 to 1.6997 a.u. and (c) the Hirshfeld surface of compound (III)[link], mapped over dnorm in the colour range −0.7519 to 1.6997 a.u..

The two-dimensional fingerprint plots for the title compounds are given in Fig. 8[link]. They reveal, as expected, that the principal contributions to the overall surface involve H⋯H contacts at 87.9% for (I)[link] (Fig. 8[link]a), 68.6% for (II)[link] (Fig. 8[link]b), and 63.3% for (III)[link] (Fig. 8[link]c). The second most important contribution to the HS for compound (I)[link] is from the N⋯H/H⋯N contacts at 8.0%; for compounds (II)[link] and (III)[link] the second most significant contributions are from the C⋯H/H⋯C contacts at 26.3 and 27.4%, respectively. For compound (I)[link], the third most important contribution to the HS is from the C⋯H/H⋯C contacts at 4.0%, while for compounds (II)[link] and (III)[link] it is from the N⋯H/H⋯N contacts at 2.6 and 5.7%, respectively. All other atom⋯atom contacts contribute less that 2% to the HS for all three compounds.

[Figure 8]
Figure 8
(a) The full two-dimensional fingerprint plot for compound (I)[link], and fingerprint plots delineated into H⋯H, N⋯H/H⋯N and C⋯H/H⋯C contacts, (b) the full two-dimensional fingerprint plot for compound (II)[link], and fingerprint plots delineated into H⋯H, C⋯H/H⋯C and N⋯H/H⋯N contacts and (c) the full two-dimensional fingerprint plot for compound (III)[link], and fingerprint plots delineated into H⋯H, C⋯H/H⋯C and N⋯H/H⋯N contacts.

5. Database survey

A search of the CSD (Version 5.41, last update November 2019; Groom et al., 2016[Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171-179.]) for the structure of 2,3,5,6-tetra­kis­(pyridin-2-yl)pyrazine gave 289 hits, of which 91 structures are polymeric. The first polymeric compound to be reported in 1995 was for a trinuclear cobalt(II) one-dimensional coordination polymer, catena-[bis­(μ2-chloro)­aceto­nitrile­tetra­chloro-[2,3,5,6-tetra­kis­(2-pyrid­yl)pyrazine]­tricobalt(II)] (CSD ref­code TUPWAC; Constable et al., 1995[Constable, E. C., Edwards, A. J., Phillips, D. & Raithby, P. (1995). Supramol. Chem. 5, 93-95.]).

A search for the structure of 2,3,5,6-pyrazine­tetra­carb­oxy­lic acid gave 92 hits, of which 64 are polymeric. Here, the first polymeric compound to be reported in 1986 was for a binuclear iron(II) polymer chain, catena-[μ2-(2,5-di­carb­oxy­pyrazine-3,6-di­carboxyl­ato-N,O)trans-di­aqua­diiron(II)] dihydrate (DUWROC; Marioni et al., 1986[Marioni, P.-A., Stoeckli-Evans, H., Marty, W., Güdel, H.-U. & Williams, A. F. (1986). Helv. Chim. Acta, 69, 1004-1011.]).

A search for the structure of tetra­kis­(amino­meth­yl)pyrazine yielded only eight hits, of which five compounds are polymeric; see for example catena-[μ2-[tetra­kis­(amino­meth­yl)pyrazine-N,N′,N′′]manganese dichloride dihydrate] (PITXEV; Ferigo et al., 1994[Ferigo, M., Bonhôte, P., Marty, W. & Stoeckli-Evans, H. (1994). J. Chem. Soc. Dalton Trans. pp. 1549-1554.]), and catena-[[μ2-2,3,5,6-tetra­kis­(amino­meth­yl)pyrazine]­bis­(μ2-chloro)­dichloro­dicopper hydrate] (PITXIZ; Ferigo et al., 1994[Ferigo, M., Bonhôte, P., Marty, W. & Stoeckli-Evans, H. (1994). J. Chem. Soc. Dalton Trans. pp. 1549-1554.]).

Recently a new ligand, 2,3,5,6-tetra­kis­(4-carb­oxy­phenyl pyrazine), has been shown to be extremely successful in forming 17 metal–organic frameworks (MOFs). It was designed by Jiang and coworkers (Jiang et al., 2017[Jiang, Y., Sun, L., Du, J., Liu, Y., Shi, H., Liang, Z. & Li, J. (2017). Cryst. Growth Des. 17, 2090-2096.]) who produced the first MOF using this ligand, viz. catena-[(μ-4,4′,4′′,4′′′-pyrazine-2,3,5,6-tetra­benzoato)bis­(N,N-di­methyl­formamide)­dizinc unknown solvate] (NAWXER; Jiang et al., 2017[Jiang, Y., Sun, L., Du, J., Liu, Y., Shi, H., Liang, Z. & Li, J. (2017). Cryst. Growth Des. 17, 2090-2096.]). Since then the ligand has been used by a number of groups, and the most recent MOF to be published is catena-[(μ-4,4′-bi­pyridine)­bis­(μ-hydroxo)bis­[μ-di­hydrogen 4,4′,4′′,4′′′-(pyrazine-2,3,5,6-tetra­yl)tetra­benzoato]trinickel unknown solvate] (HOQTUF; Wang et al., 2019[Wang, L., Zou, R., Guo, W., Gao, S., Meng, W., Yang, J., Chen, X. & Zou, R. (2019). Inorg. Chem. Commun. 104, 78-82.]).

In relation to the structure of compound (III)[link], a search for the substructure pyrrolo­[3,4-b]pyrazine yielded only two hits. They concern di­pyrrolo­[3,4-b:3′,4′-e]pyrazine structures that possess inversion symmetry, viz. 2,6-dibenzyl-1,2,3,5,6,7-hexa­hydro­dipyrrolo­[3,4-b:3′,4′-e]pyrazine (EXUHIO; Gasser & Stoeckli-Evans, 2004[Gasser, G. & Stoeckli-Evans, H. (2004). Acta Cryst. C60, o514-o516.]) and 2,6-bis­(4-meth­oxy­benz­yl)-1,2,3,5,6,7-hexa­hydro­dipyrrolo­[3,4-b:3′,4′-e]pyrazine (EXU­HOU; Gasser & Stoeckli-Evans, 2004[Gasser, G. & Stoeckli-Evans, H. (2004). Acta Cryst. C60, o514-o516.]). They were prepared during attempts to form 1,2,3,5,6,7-hexa­hydro-2,4,6,8-tetra­aza-s-indacene by reacting 2,3,5,6-tetra­kis­(bromo­meth­yl)pyrazine (Ferigo et al., 1994[Ferigo, M., Bonhôte, P., Marty, W. & Stoeckli-Evans, H. (1994). J. Chem. Soc. Dalton Trans. pp. 1549-1554.]; TOJXUN: Assoumatine & Stoeckli-Evans, 2014[Assoumatine, T. & Stoeckli-Evans, H. (2014). Acta Cryst. E70, 51-53.]) with the corresponding amines. In contrast to (III)[link], where the pyrrolo ring is planar (r.m.s. deviation = 0.029 Å) and inclined by only 2.00 (12)° to the pyrazine ring, here the pyrrolo groups have envelope conformations with the pyrrolo N atoms as the flaps. Their mean planes are inclined to the pyrazine ring by 7.88 (16)° in EXUHIO and by 8.05 (7)° in EXUHOU.

6. Synthesis and crystallization

Synthesis of 1,1′,1′′,1′′′-(pyrazine-2,3,5,6-tetra­yl) tetra­kis­(N,N-di­methyl­methanamine) (I)[link]:

A large excess of dimethyl amine hydro­chloride in water was neutralized with NaOH in an ice bath. Me2NH formed in situ as a gas and was directly condensed in a round-bottom flask in an acetone/liquid N2 bath at about 213 K using a weak vacuum. Once a sufficient qu­antity of liquid amine had formed, a solution of 2,3,5,6-tetra­kis­(bromo­meth­yl)pyrazine (0.4530 g, 1 mmol) in 50 ml of CH2Cl2 was added dropwise at low temperature (ca 243 K). The reaction was left for about 4 h, allowing the temperature rise to RT. The excess amine was allowed to evaporate off before the solvent was gassed off. The residue obtained was dissolved in 40 ml of MeOH and passed through a resin column (15 g of Dowex 1 X8) previously charged with OH ions in order to exchange the HBr mol­ecules, still attached to the ligand, by H2O mol­ecules. About 150 ml were used as eluent. Solvent evaporation yielded 0.27 g (87%) of a light-yellow powder of compound (I)[link]. Colourless block-like crystals were obtained by slow diffusion of hexane into a solution of the ligand in di­chloro­methane.

1H NMR (CDCl3, 200 MHz, ppm): 3.65 (s, 8H, CH2), 2.15 (s, 12H, CH3). 13C NMR (D2O, 400 MHz, ppm): 152.16, 62.53, 46.54. IR (KBr pellet, cm−1): 2974 (s), 2942 (s), 2854 (m), 2820 (vs), 2772 (vs), 1635 (b), 1456 (s), 1414 (m), 1348 (s), 1259 (s), 1204 (m), 1168 (m), 1027 (vs), 987 (m), 841 (s). MS (EI, 70 eV), m/z: 310 (MH+), 264, 178. Anal. for C16H32N6 (308.5 g mol−1) Calculated (%) C 62.30, H 10.46, N 27.24. Found (%) C 61.86, H 10.73, N 27.50.

Synthesis of N,N,N′′,N′′′-[pyrazine-2,3,5,6-tetra­yltetra­kis(methyl­ene)]tetra­kis­(N-methyl­aniline) (II):

A solution of 2,3,5,6-tetra­kis­(bromo­meth­yl)pyrazine (0.4530 g, 1 mmol) in 35 ml of CH3CN was added dropwise to a suspension of N-methyl­aniline (1.2 ml, 10 mmol) and Na2CO3 (5.3 g, 50 mmol) in 25 ml of CH3CN. The colour changed immediately from light to deep yellow. The mixture was refluxed for ca 2 h, followed by TLC and then cooled to RT. The white precipitate (NaBr and excess Na2CO3) was filtered off and the filtrate was evaporated under vacuum. The residue was dissolved in hexane and the insoluble yellow powder obtained was recovered, washed with more hexane and then dried to yield 0.335 g (60%) of compound (II)[link]. Pale-greenish-yellow block-like crystals were obtained by slow evaporation of a CDCl3 solution of (II)[link] in an NMR tube.

1H NMR (CDCl3, 200 MHz, ppm): 7.14 (t, 8H, ph), 6.68 (m, 12H, ph), 4.58 (s, 8H, CH2), 2.79 (s, 12H, CH3). 13C NMR (CD3OD, 400 MHz, ppm): 149.64, 149.31, 128.94, 116.92, 113.17, 54.75, 39.46. IR (KBr pellet, cm−1): 2926 (w), 1601 (s), 1508 (vs), 1446 (m), 1377 (m), 1366 (m), 1313 (m), 1257 (m), 1212 (m), 1117 (w), 993 (w), 820 (w), 745 (s), 689 (m). MS (EI, 70 eV), m/z: 594 (MK+), 374, 291. Analysis for C36H40N6 (556.7 g mol−1) Calculated (%) C 77.66, H 7.24, N 15.09. Found (%) C 76.82, H 7.19, N 15.07.

Synthesis of N,N′-[(6-phenyl-6,7-di­hydro-5H-pyrrolo[3,4-b]pyrazine-2,3-di­yl)bis­(methyl­ene)]bis­(N-methyl­aniline) (III)[link]:

Hexagonal pale-yellow plate-like crystals of compound (III)[link] were obtained several times when reacting (II)[link] with different metal salts, such as Zn(ClO4)2 (in excess), MnCl2·4H2O and Ni(AcO)2·4H2O. No spectroscopic or other analytical data are available for this compound.

7. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 4[link]. The C-bound H atoms were included in calculated positions and treated as riding on their parent C atom: C—H = 0.93–0.97 Å with Uiso(H) =1.5Ueq(C-meth­yl) and 1.2Ueq(C) for other H atoms. Note for compound (III)[link]: using the Stoe IPDS I, a one-circle diffractometer, to measure data for the triclinic system often only 93% of the Ewald sphere is accessible. Hence, the diffrn_reflns_Laue_measured_fraction_full of 0.939 is below the required minimum of 0.95.

Table 4
Experimental details

  (I) (II) (III)
Crystal data
Chemical formula C16H32N6 C36H40N6 C28H29N5
Mr 308.47 556.74 435.56
Crystal system, space group Monoclinic, P21/n Triclinic, P[\overline{1}] Triclinic, P[\overline{1}]
Temperature (K) 293 293 293
a, b, c (Å) 9.7577 (14), 10.348 (2), 9.9118 (16) 8.6753 (10), 8.9160 (11), 10.0631 (10) 8.686 (1), 9.7731 (11), 14.3948 (16)
α, β, γ (°) 90, 101.663 (15), 90 85.774 (10), 73.468 (11), 82.467 (11) 85.915 (13), 75.349 (13), 78.891 (13)
V3) 980.2 (3) 739.21 (15) 1159.8 (2)
Z 2 1 2
Radiation type Mo Kα Mo Kα Mo Kα
μ (mm−1) 0.07 0.08 0.08
Crystal size (mm) 0.53 × 0.53 × 0.26 0.38 × 0.30 × 0.27 0.45 × 0.35 × 0.10
 
Data collection
Diffractometer Stoe–Siemens AED2, 4-circle Stoe–Siemens AED2, 4-circle Stoe IPDS 1
No. of measured, independent and observed [I > 2σ(I)] reflections 3347, 1818, 1111 5354, 2741, 1913 8653, 3953, 1518
Rint 0.055 0.031 0.051
(sin θ/λ)max−1) 0.605 0.605 0.600
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.060, 0.154, 1.10 0.049, 0.108, 1.12 0.035, 0.079, 0.68
No. of reflections 1818 2741 3953
No. of parameters 105 193 301
H-atom treatment H-atom parameters constrained H-atom parameters constrained H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.15, −0.12 0.13, −0.15 0.12, −0.12
Computer programs: STADI4 (Stoe & Cie, 1997[Stoe & Cie (1997). STADI4 and X-RED. Stoe & Cie GmbH, Darmstadt, Germany.]), EXPOSE, CELL and INTEGRATE in IPDS-I (Stoe & Cie, 2004[Stoe & Cie (2004). IPDSI Bedienungshandbuch. Stoe & Cie GmbH, Darmstadt, Germany.]), X-RED (Stoe & Cie, 1997[Stoe & Cie (1997). STADI4 and X-RED. Stoe & Cie GmbH, Darmstadt, Germany.]), SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]), Mercury (Macrae et al., 2020[Macrae, C. F., Sovago, I., Cottrell, S. J., Galek, P. T. A., McCabe, P., Pidcock, E., Platings, M., Shields, G. P., Stevens, J. S., Towler, M. & Wood, P. A. (2020). J. Appl. Cryst. 53, 226-235.]), SHELXL2018/3 (Sheldrick, 2015[Sheldrick, G. M. (2015). Acta Cryst. C71, 3-8.]), PLATON (Spek, 2020[Spek, A. L. (2020). Acta Cryst. E76, 1-11.]) and publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

Supporting information


Computing details top

Data collection: STADI4 (Stoe & Cie, 1997) for (I), (II); EXPOSE in IPDS-I (Stoe & Cie, 2004) for (III). Cell refinement: STADI4 (Stoe & Cie, 1997) for (I), (II); CELL in IPDS-I (Stoe & Cie, 2004) for (III). Data reduction: X-RED (Stoe & Cie, 1997) for (I), (II); INTEGRATE in IPDS-I (Stoe & Cie, 2004) for (III). For all structures, program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2018/3 (Sheldrick, 2015); molecular graphics: Mercury (Macrae et al., 2020); software used to prepare material for publication: SHELXL2018/3 (Sheldrick, 2015), PLATON (Spek, 2020) and publCIF (Westrip, 2010).

1,1',1'',1'''-(Pyrazine-2,3,5,6-tetrayl)tetrakis(N,N-dimethylmethanamine) (I) top
Crystal data top
C16H32N6F(000) = 340
Mr = 308.47Dx = 1.045 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
a = 9.7577 (14) ÅCell parameters from 22 reflections
b = 10.348 (2) Åθ = 12.6–18.1°
c = 9.9118 (16) ŵ = 0.07 mm1
β = 101.663 (15)°T = 293 K
V = 980.2 (3) Å3Block, colourless
Z = 20.53 × 0.53 × 0.26 mm
Data collection top
Stoe–Siemens AED2, 4-circle
diffractometer
Rint = 0.055
Radiation source: fine-focus sealed tubeθmax = 25.5°, θmin = 2.7°
Plane graphite monochromatorh = 1111
ω/\2q scansk = 012
3347 measured reflectionsl = 1111
1818 independent reflections2 standard reflections every 60 min
1111 reflections with I > 2σ(I) intensity decay: 1%
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.060H-atom parameters constrained
wR(F2) = 0.154 w = 1/[σ2(Fo2) + (0.0488P)2 + 0.2847P]
where P = (Fo2 + 2Fc2)/3
S = 1.10(Δ/σ)max < 0.001
1818 reflectionsΔρmax = 0.15 e Å3
105 parametersΔρmin = 0.12 e Å3
0 restraintsExtinction correction: (SHELXL2018/3; Sheldrick, 2015), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.043 (7)
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
N10.07379 (18)0.10665 (19)0.46684 (19)0.0504 (5)
N20.2065 (2)0.0663 (2)0.2414 (2)0.0657 (7)
N30.1836 (2)0.1754 (2)0.8033 (2)0.0699 (7)
C10.0393 (2)0.0085 (2)0.3779 (2)0.0465 (6)
C20.0345 (2)0.0981 (2)0.5885 (2)0.0476 (6)
C30.0864 (3)0.0171 (3)0.2426 (2)0.0576 (7)
H3A0.0099710.0080610.1685670.069*
H3B0.1111310.1057460.2266630.069*
C40.2207 (4)0.0957 (4)0.1004 (3)0.1046 (12)
H4A0.2345450.0169580.0537520.157*
H4B0.1372430.1376980.0523950.157*
H4C0.2995130.1517130.1027100.157*
C50.3335 (3)0.0092 (4)0.3188 (3)0.0979 (12)
H5C0.4098620.0682970.3219750.147*
H5B0.3220270.0090640.4108920.147*
H5A0.3528580.0696240.2751330.147*
C60.0739 (3)0.2095 (2)0.6863 (3)0.0615 (7)
H6A0.1053480.2811270.6372890.074*
H6B0.0082030.2376560.7195050.074*
C70.3174 (3)0.1604 (4)0.7623 (4)0.1168 (15)
H7A0.3465080.2420540.7317870.175*
H7B0.3082880.0987090.6886860.175*
H7C0.3860120.1303480.8394650.175*
C80.1949 (4)0.2720 (3)0.9118 (3)0.1000 (12)
H8A0.1078520.2771660.9425470.150*
H8B0.2159250.3545600.8767070.150*
H8C0.2682550.2480050.9875900.150*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0471 (11)0.0513 (12)0.0535 (12)0.0003 (9)0.0121 (9)0.0005 (10)
N20.0654 (14)0.0752 (16)0.0629 (14)0.0117 (12)0.0279 (11)0.0066 (12)
N30.0630 (14)0.0758 (16)0.0663 (14)0.0068 (12)0.0021 (11)0.0189 (12)
C10.0433 (12)0.0490 (14)0.0465 (13)0.0037 (11)0.0076 (10)0.0006 (12)
C20.0420 (12)0.0478 (14)0.0522 (14)0.0030 (11)0.0076 (10)0.0032 (11)
C30.0597 (15)0.0629 (17)0.0520 (14)0.0059 (13)0.0152 (12)0.0041 (12)
C40.130 (3)0.117 (3)0.081 (2)0.032 (2)0.056 (2)0.002 (2)
C50.0565 (17)0.145 (3)0.096 (2)0.001 (2)0.0259 (17)0.019 (2)
C60.0660 (17)0.0529 (15)0.0666 (16)0.0012 (13)0.0157 (13)0.0089 (13)
C70.060 (2)0.154 (4)0.131 (3)0.008 (2)0.0089 (19)0.058 (3)
C80.105 (3)0.111 (3)0.078 (2)0.022 (2)0.0064 (19)0.037 (2)
Geometric parameters (Å, º) top
N1—C21.340 (3)C4—H4B0.9600
N1—C11.342 (3)C4—H4C0.9600
N2—C51.446 (4)C5—H5C0.9600
N2—C31.457 (3)C5—H5B0.9600
N2—C41.463 (3)C5—H5A0.9600
N3—C71.452 (4)C6—H6A0.9700
N3—C61.454 (3)C6—H6B0.9700
N3—C81.456 (3)C7—H7A0.9600
C1—C2i1.394 (3)C7—H7B0.9600
C1—C31.506 (3)C7—H7C0.9600
C2—C61.505 (3)C8—H8A0.9600
C3—H3A0.9700C8—H8B0.9600
C3—H3B0.9700C8—H8C0.9600
C4—H4A0.9600
C2—N1—C1117.5 (2)N2—C5—H5C109.5
C5—N2—C3111.0 (2)N2—C5—H5B109.5
C5—N2—C4110.8 (2)H5C—C5—H5B109.5
C3—N2—C4111.3 (2)N2—C5—H5A109.5
C7—N3—C6111.2 (2)H5C—C5—H5A109.5
C7—N3—C8110.0 (2)H5B—C5—H5A109.5
C6—N3—C8110.9 (2)N3—C6—C2112.3 (2)
N1—C1—C2i121.0 (2)N3—C6—H6A109.1
N1—C1—C3117.3 (2)C2—C6—H6A109.1
C2i—C1—C3121.7 (2)N3—C6—H6B109.1
N1—C2—C1i121.5 (2)C2—C6—H6B109.1
N1—C2—C6116.5 (2)H6A—C6—H6B107.9
C1i—C2—C6121.9 (2)N3—C7—H7A109.5
N2—C3—C1111.3 (2)N3—C7—H7B109.5
N2—C3—H3A109.4H7A—C7—H7B109.5
C1—C3—H3A109.4N3—C7—H7C109.5
N2—C3—H3B109.4H7A—C7—H7C109.5
C1—C3—H3B109.4H7B—C7—H7C109.5
H3A—C3—H3B108.0N3—C8—H8A109.5
N2—C4—H4A109.5N3—C8—H8B109.5
N2—C4—H4B109.5H8A—C8—H8B109.5
H4A—C4—H4B109.5N3—C8—H8C109.5
N2—C4—H4C109.5H8A—C8—H8C109.5
H4A—C4—H4C109.5H8B—C8—H8C109.5
H4B—C4—H4C109.5
C2—N1—C1—C2i0.1 (3)N1—C1—C3—N2103.4 (2)
C2—N1—C1—C3178.68 (19)C2i—C1—C3—N275.2 (3)
C1—N1—C2—C1i0.1 (3)C7—N3—C6—C271.6 (3)
C1—N1—C2—C6179.79 (19)C8—N3—C6—C2165.7 (2)
C5—N2—C3—C177.0 (3)N1—C2—C6—N3108.7 (2)
C4—N2—C3—C1159.1 (2)C1i—C2—C6—N371.4 (3)
Symmetry code: (i) x, y, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H3A···N3i0.972.623.261 (4)124
Symmetry code: (i) x, y, z+1.
N,N',N'',N'''-[Pyrazine-2,3,5,6\ tetrayltetrakis(methylene)]tetrakis(N-methylaniline) (II) top
Crystal data top
C36H40N6Z = 1
Mr = 556.74F(000) = 298
Triclinic, P1Dx = 1.251 Mg m3
a = 8.6753 (10) ÅMo Kα radiation, λ = 0.71073 Å
b = 8.9160 (11) ÅCell parameters from 28 reflections
c = 10.0631 (10) Åθ = 12.5–17.6°
α = 85.774 (10)°µ = 0.08 mm1
β = 73.468 (11)°T = 293 K
γ = 82.467 (11)°Block, pale-greenish-yellow
V = 739.21 (15) Å30.38 × 0.30 × 0.27 mm
Data collection top
Stoe–Siemens AED2, 4-circle
diffractometer
Rint = 0.031
Radiation source: fine-focus sealed tubeθmax = 25.5°, θmin = 2.1°
Plane graphite monochromatorh = 910
ω/\2q scansk = 1010
5354 measured reflectionsl = 1212
2741 independent reflections2 standard reflections every 60 min
1913 reflections with I > 2σ(I) intensity decay: 1%
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.049H-atom parameters constrained
wR(F2) = 0.108 w = 1/[σ2(Fo2) + (0.0254P)2 + 0.254P]
where P = (Fo2 + 2Fc2)/3
S = 1.12(Δ/σ)max < 0.001
2741 reflectionsΔρmax = 0.13 e Å3
193 parametersΔρmin = 0.14 e Å3
0 restraintsExtinction correction: (SHELXL2018/3; Sheldrick 2015), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.026 (3)
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
N10.46201 (19)0.59971 (18)0.89913 (16)0.0393 (4)
N20.5739 (2)0.31235 (19)0.66461 (17)0.0454 (4)
N30.2493 (2)0.85914 (19)0.95305 (17)0.0481 (5)
C10.5585 (2)0.4702 (2)0.86471 (19)0.0366 (5)
C20.4027 (2)0.6301 (2)1.0334 (2)0.0378 (5)
C30.6246 (2)0.4442 (2)0.7110 (2)0.0437 (5)
H3A0.5908180.5334440.6605080.052*
H3B0.7418790.4330340.6872570.052*
C40.4248 (3)0.3268 (2)0.63526 (19)0.0429 (5)
C50.3070 (3)0.4493 (3)0.6795 (2)0.0502 (6)
H50.3286370.5245820.7286040.060*
C60.1604 (3)0.4603 (3)0.6515 (2)0.0619 (7)
H60.0839830.5427940.6822240.074*
C70.1237 (3)0.3508 (3)0.5785 (3)0.0674 (7)
H70.0241390.3591850.5592880.081*
C80.2367 (3)0.2306 (3)0.5354 (3)0.0661 (7)
H80.2129660.1558800.4869850.079*
C90.3863 (3)0.2167 (2)0.5618 (2)0.0549 (6)
H90.4616010.1336650.5304810.066*
C100.7008 (3)0.2013 (3)0.5894 (3)0.0645 (7)
H10A0.7994060.2088320.6125830.097*
H10B0.7174710.2203960.4914340.097*
H10C0.6693450.1015220.6144010.097*
C110.2938 (3)0.7782 (2)1.0686 (2)0.0488 (6)
H11A0.1956860.7569711.1389340.059*
H11B0.3483950.8436001.1086030.059*
C120.1177 (2)0.8292 (2)0.9122 (2)0.0431 (5)
C130.0121 (3)0.7258 (3)0.9845 (2)0.0586 (6)
H130.0328490.6710201.0610370.070*
C140.1220 (3)0.7040 (3)0.9440 (3)0.0697 (7)
H140.1911440.6359930.9949960.084*
C150.1562 (3)0.7802 (3)0.8302 (3)0.0690 (7)
H150.2470730.7650060.8035640.083*
C160.0517 (3)0.8795 (3)0.7571 (3)0.0643 (7)
H160.0721290.9311900.6790590.077*
C170.0822 (3)0.9052 (2)0.7956 (2)0.0516 (6)
H170.1499600.9737160.7437060.062*
C180.3667 (3)0.9499 (3)0.8637 (3)0.0633 (7)
H18A0.4070360.9067720.7740330.095*
H18B0.4547750.9522130.9033520.095*
H18C0.3162861.0511470.8544970.095*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0443 (10)0.0408 (10)0.0350 (9)0.0041 (8)0.0144 (7)0.0032 (7)
N20.0498 (11)0.0481 (10)0.0390 (10)0.0057 (8)0.0163 (8)0.0112 (8)
N30.0541 (11)0.0469 (11)0.0455 (10)0.0000 (9)0.0210 (9)0.0016 (8)
C10.0371 (11)0.0405 (11)0.0347 (11)0.0066 (9)0.0126 (9)0.0044 (9)
C20.0400 (11)0.0397 (11)0.0366 (11)0.0044 (9)0.0147 (9)0.0040 (9)
C30.0454 (12)0.0489 (12)0.0360 (11)0.0029 (10)0.0106 (9)0.0039 (9)
C40.0523 (13)0.0451 (12)0.0314 (11)0.0027 (10)0.0142 (9)0.0021 (9)
C50.0551 (14)0.0576 (14)0.0379 (12)0.0042 (11)0.0159 (10)0.0098 (10)
C60.0490 (14)0.0793 (18)0.0521 (14)0.0084 (13)0.0120 (11)0.0046 (13)
C70.0535 (15)0.090 (2)0.0637 (16)0.0169 (14)0.0239 (13)0.0119 (15)
C80.0831 (19)0.0582 (16)0.0719 (17)0.0206 (14)0.0412 (15)0.0038 (13)
C90.0747 (16)0.0424 (13)0.0524 (14)0.0010 (11)0.0275 (12)0.0030 (10)
C100.0631 (16)0.0667 (16)0.0613 (15)0.0207 (13)0.0210 (12)0.0223 (13)
C110.0574 (14)0.0506 (13)0.0406 (12)0.0052 (10)0.0210 (10)0.0074 (10)
C120.0464 (12)0.0381 (11)0.0429 (12)0.0086 (9)0.0140 (10)0.0078 (9)
C130.0673 (16)0.0563 (15)0.0519 (14)0.0083 (12)0.0173 (12)0.0048 (11)
C140.0597 (16)0.0732 (18)0.0723 (18)0.0179 (13)0.0071 (14)0.0057 (14)
C150.0550 (15)0.0744 (18)0.083 (2)0.0020 (14)0.0280 (14)0.0203 (15)
C160.0704 (17)0.0633 (16)0.0654 (16)0.0085 (13)0.0356 (14)0.0040 (13)
C170.0555 (14)0.0492 (13)0.0509 (13)0.0012 (11)0.0196 (11)0.0026 (10)
C180.0677 (16)0.0617 (15)0.0676 (16)0.0143 (13)0.0287 (13)0.0036 (13)
Geometric parameters (Å, º) top
N1—C21.336 (2)C8—H80.9300
N1—C11.339 (2)C9—H90.9300
N2—C41.395 (3)C10—H10A0.9600
N2—C101.454 (3)C10—H10B0.9600
N2—C31.459 (3)C10—H10C0.9600
N3—C121.382 (3)C11—H11A0.9700
N3—C111.442 (2)C11—H11B0.9700
N3—C181.445 (3)C12—C131.400 (3)
C1—C2i1.395 (3)C12—C171.401 (3)
C1—C31.512 (3)C13—C141.378 (3)
C2—C111.521 (3)C13—H130.9300
C3—H3A0.9700C14—C151.374 (4)
C3—H3B0.9700C14—H140.9300
C4—C91.398 (3)C15—C161.371 (4)
C4—C51.398 (3)C15—H150.9300
C5—C61.369 (3)C16—C171.375 (3)
C5—H50.9300C16—H160.9300
C6—C71.384 (3)C17—H170.9300
C6—H60.9300C18—H18A0.9600
C7—C81.359 (4)C18—H18B0.9600
C7—H70.9300C18—H18C0.9600
C8—C91.386 (3)
C2—N1—C1118.46 (16)C7—C8—C9121.7 (2)
C4—N2—C10117.64 (17)C7—C8—H8119.2
C4—N2—C3118.71 (16)C9—C8—H8119.2
C10—N2—C3117.17 (18)C8—C9—C4120.4 (2)
C12—N3—C11122.00 (18)C8—C9—H9119.8
C12—N3—C18120.07 (17)C4—C9—H9119.8
C11—N3—C18116.70 (18)N3—C12—C13122.77 (19)
N1—C1—C2i120.79 (16)N3—C12—C17120.5 (2)
N1—C1—C3115.85 (16)C13—C12—C17116.7 (2)
C2i—C1—C3123.33 (17)C14—C13—C12121.0 (2)
N1—C2—C1i120.74 (17)C14—C13—H13119.5
N1—C2—C11117.03 (17)C12—C13—H13119.5
C1i—C2—C11122.23 (17)C15—C14—C13121.6 (2)
N2—C3—C1114.84 (17)C15—C14—H14119.2
N2—C3—H3A108.6C13—C14—H14119.2
C1—C3—H3A108.6C16—C15—C14117.7 (2)
N2—C3—H3B108.6C16—C15—H15121.1
C1—C3—H3B108.6C14—C15—H15121.1
H3A—C3—H3B107.5C15—C16—C17122.1 (2)
N3—C11—C2115.02 (17)C15—C16—H16119.0
N3—C11—H11A108.5C17—C16—H16119.0
C2—C11—H11A108.5C16—C17—C12120.8 (2)
N3—C11—H11B108.5C16—C17—H17119.6
C2—C11—H11B108.5C12—C17—H17119.6
H11A—C11—H11B107.5N3—C18—H18A109.5
N2—C4—C9120.81 (19)N3—C18—H18B109.5
N2—C4—C5121.91 (19)H18A—C18—H18B109.5
C9—C4—C5117.3 (2)N3—C18—H18C109.5
C6—C5—C4121.1 (2)H18A—C18—H18C109.5
C6—C5—H5119.5H18B—C18—H18C109.5
C4—C5—H5119.5N2—C10—H10A109.5
C5—C6—C7121.2 (2)N2—C10—H10B109.5
C5—C6—H6119.4H10A—C10—H10B109.5
C7—C6—H6119.4N2—C10—H10C109.5
C8—C7—C6118.4 (2)H10A—C10—H10C109.5
C8—C7—H7120.8H10B—C10—H10C109.5
C6—C7—H7120.8
C2—N1—C1—C2i0.5 (3)C4—C5—C6—C70.1 (4)
C2—N1—C1—C3178.66 (17)C5—C6—C7—C80.4 (4)
C1—N1—C2—C1i0.5 (3)C6—C7—C8—C90.6 (4)
C1—N1—C2—C11179.92 (17)C7—C8—C9—C40.5 (4)
C4—N2—C3—C183.8 (2)N2—C4—C9—C8178.8 (2)
C10—N2—C3—C1125.0 (2)C5—C4—C9—C80.2 (3)
N1—C1—C3—N2117.34 (19)C11—N3—C12—C134.2 (3)
C2i—C1—C3—N264.5 (2)C18—N3—C12—C13171.1 (2)
C12—N3—C11—C286.2 (2)C11—N3—C12—C17177.13 (19)
C18—N3—C11—C281.1 (2)C18—N3—C12—C1710.2 (3)
N1—C2—C11—N38.2 (3)N3—C12—C13—C14177.1 (2)
C1i—C2—C11—N3172.42 (18)C17—C12—C13—C141.7 (3)
C10—N2—C4—C914.5 (3)C12—C13—C14—C151.2 (4)
C3—N2—C4—C9165.50 (19)C13—C14—C15—C160.1 (4)
C10—N2—C4—C5166.6 (2)C14—C15—C16—C170.8 (4)
C3—N2—C4—C515.6 (3)C15—C16—C17—C120.3 (4)
N2—C4—C5—C6178.9 (2)N3—C12—C17—C16177.8 (2)
C9—C4—C5—C60.0 (3)C13—C12—C17—C161.0 (3)
Symmetry code: (i) x+1, y+1, z+2.
Hydrogen-bond geometry (Å, º) top
Cg2 and Cg3 are the centroids of rings C4–C9 and C12–C17, respectively.
D—H···AD—HH···AD···AD—H···A
C5—H5···N10.932.503.331 (3)149
C6—H6···Cg30.932.993.804 (3)147
C3—H3A···Cg2ii0.972.833.561 (2)133
Symmetry code: (ii) x+1, y+1, z+1.
N,N'-[(6-Phenyl-6,7-dihydro-5H-pyrrolo[3,4-\ b]pyrazine-2,3-diyl)bis(methylene)]bis(N-methylaniline) (III) top
Crystal data top
C28H29N5Z = 2
Mr = 435.56F(000) = 464
Triclinic, P1Dx = 1.247 Mg m3
a = 8.686 (1) ÅMo Kα radiation, λ = 0.71073 Å
b = 9.7731 (11) ÅCell parameters from 5000 reflections
c = 14.3948 (16) Åθ = 1.7–26.1°
α = 85.915 (13)°µ = 0.08 mm1
β = 75.349 (13)°T = 293 K
γ = 78.891 (13)°Hexagonal plate, pale yellow
V = 1159.8 (2) Å30.45 × 0.35 × 0.10 mm
Data collection top
Stoe IPDS 1
diffractometer
1518 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.051
Plane graphite monochromatorθmax = 25.3°, θmin = 2.1°
φ rotation scansh = 1010
8653 measured reflectionsk = 1111
3953 independent reflectionsl = 1717
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.035H-atom parameters constrained
wR(F2) = 0.079 w = 1/[σ2(Fo2) + (0.0308P)2]
where P = (Fo2 + 2Fc2)/3
S = 0.68(Δ/σ)max < 0.001
3953 reflectionsΔρmax = 0.12 e Å3
301 parametersΔρmin = 0.12 e Å3
0 restraintsExtinction correction: (SHELXL2018/3; Sheldrick, 2015), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.0154 (11)
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
N10.4060 (2)0.8786 (2)0.20916 (11)0.0559 (5)
N20.2666 (2)0.9790 (2)0.05437 (12)0.0596 (6)
N30.5915 (2)0.6863 (2)0.00687 (11)0.0641 (6)
N40.0765 (2)1.1354 (2)0.19845 (12)0.0567 (5)
N50.2256 (2)0.9508 (2)0.39598 (12)0.0607 (6)
C10.2797 (3)0.9865 (2)0.21849 (14)0.0536 (6)
C20.4566 (2)0.8223 (2)0.12258 (14)0.0510 (6)
C30.3862 (3)0.8699 (3)0.04787 (13)0.0522 (6)
C40.2133 (2)1.0385 (2)0.14142 (15)0.0550 (6)
C50.5911 (3)0.7029 (2)0.09341 (13)0.0611 (7)
H5A0.6929530.7242260.0988420.073*
H5B0.5701130.6197430.1317380.073*
C60.4643 (2)0.7825 (2)0.03875 (13)0.0577 (7)
H6A0.3882740.7333190.0552100.069*
H6B0.5085920.8387260.0936820.069*
C70.6870 (3)0.5773 (3)0.06142 (15)0.0559 (6)
C80.8004 (3)0.4812 (3)0.02614 (15)0.0620 (7)
H80.8108940.4894350.0358320.074*
C90.8976 (3)0.3735 (3)0.08282 (17)0.0725 (8)
H90.9725060.3098930.0582150.087*
C100.8853 (3)0.3590 (3)0.17452 (19)0.0773 (8)
H100.9515630.2865670.2120660.093*
C110.7738 (3)0.4528 (3)0.21026 (16)0.0764 (8)
H110.7647760.4435270.2724100.092*
C120.6751 (3)0.5608 (3)0.15511 (15)0.0665 (7)
H120.5998990.6231640.1803670.080*
C130.2210 (3)1.0516 (2)0.31746 (14)0.0602 (7)
H13A0.2876581.1190630.3212360.072*
H13B0.1107581.1014540.3247800.072*
C140.1121 (3)0.8654 (3)0.42226 (14)0.0560 (6)
C150.0211 (3)0.8838 (3)0.38231 (15)0.0629 (7)
H150.0325020.9535510.3358420.076*
C160.1360 (3)0.8000 (3)0.41067 (19)0.0781 (8)
H160.2244040.8146560.3834650.094*
C170.1225 (4)0.6956 (3)0.4781 (2)0.0906 (9)
H170.1996300.6384720.4963650.109*
C180.0080 (5)0.6771 (3)0.51850 (19)0.0919 (10)
H180.0175610.6073460.5652180.110*
C190.1240 (3)0.7587 (3)0.49158 (17)0.0713 (8)
H190.2114260.7432060.5196030.086*
C200.3718 (3)0.9195 (3)0.43102 (17)0.0861 (9)
H20A0.4356850.9906270.4085680.129*
H20B0.4332100.8307630.4076650.129*
H20C0.3431730.9163590.4999730.129*
C210.0812 (3)1.1664 (2)0.14886 (15)0.0651 (7)
H21A0.1065501.2377900.1830890.078*
H21B0.0776621.2029140.0848400.078*
C220.1951 (3)1.2457 (3)0.24527 (14)0.0534 (6)
C230.1678 (3)1.3796 (3)0.24765 (15)0.0688 (7)
H230.0691341.4020280.2138890.083*
C240.2859 (4)1.4813 (3)0.29992 (19)0.0860 (9)
H240.2648071.5708610.3011920.103*
C250.4332 (4)1.4517 (4)0.34971 (19)0.0920 (11)
H250.5115671.5196980.3852880.110*
C260.4620 (3)1.3199 (4)0.34573 (18)0.0911 (10)
H260.5621131.2990000.3780990.109*
C270.3461 (3)1.2173 (3)0.29485 (16)0.0719 (8)
H270.3687661.1283930.2935590.086*
C280.1287 (3)1.0303 (3)0.15362 (17)0.0805 (8)
H28A0.2002920.9833590.2015930.121*
H28B0.0361120.9639500.1230960.121*
H28C0.1843521.0739960.1064620.121*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0524 (11)0.0660 (15)0.0465 (11)0.0088 (11)0.0077 (9)0.0042 (9)
N20.0533 (12)0.0728 (15)0.0465 (11)0.0058 (11)0.0064 (9)0.0024 (10)
N30.0620 (12)0.0785 (16)0.0446 (11)0.0103 (12)0.0146 (9)0.0111 (10)
N40.0522 (12)0.0551 (14)0.0605 (11)0.0069 (11)0.0106 (10)0.0064 (10)
N50.0562 (13)0.0813 (17)0.0459 (11)0.0163 (12)0.0104 (10)0.0081 (10)
C10.0503 (14)0.0603 (18)0.0468 (13)0.0137 (13)0.0020 (11)0.0047 (11)
C20.0461 (13)0.0629 (17)0.0413 (13)0.0085 (13)0.0070 (11)0.0013 (12)
C30.0469 (13)0.0650 (17)0.0419 (13)0.0106 (13)0.0056 (11)0.0000 (12)
C40.0498 (14)0.0601 (17)0.0505 (14)0.0082 (13)0.0063 (12)0.0022 (12)
C50.0567 (14)0.0749 (19)0.0467 (13)0.0009 (14)0.0100 (11)0.0089 (12)
C60.0524 (14)0.0736 (18)0.0449 (12)0.0084 (13)0.0094 (11)0.0039 (12)
C70.0486 (14)0.0627 (18)0.0532 (14)0.0095 (14)0.0052 (11)0.0076 (12)
C80.0555 (14)0.0709 (19)0.0563 (14)0.0066 (15)0.0098 (12)0.0068 (13)
C90.0645 (17)0.069 (2)0.0777 (18)0.0034 (15)0.0112 (14)0.0085 (15)
C100.0739 (19)0.074 (2)0.0766 (18)0.0108 (17)0.0001 (15)0.0247 (15)
C110.0800 (19)0.088 (2)0.0597 (15)0.0135 (18)0.0103 (14)0.0186 (15)
C120.0623 (16)0.080 (2)0.0562 (15)0.0069 (15)0.0135 (12)0.0119 (13)
C130.0618 (16)0.0653 (18)0.0513 (13)0.0143 (13)0.0053 (11)0.0109 (13)
C140.0589 (16)0.0647 (19)0.0397 (13)0.0072 (15)0.0032 (12)0.0143 (12)
C150.0598 (16)0.074 (2)0.0540 (14)0.0175 (15)0.0057 (13)0.0109 (13)
C160.070 (2)0.085 (2)0.0761 (18)0.0172 (18)0.0039 (15)0.0237 (17)
C170.092 (2)0.079 (3)0.092 (2)0.039 (2)0.0180 (18)0.0243 (19)
C180.127 (3)0.069 (2)0.0706 (19)0.018 (2)0.006 (2)0.0067 (15)
C190.086 (2)0.064 (2)0.0615 (16)0.0086 (17)0.0154 (14)0.0066 (14)
C200.0670 (17)0.122 (3)0.0789 (17)0.0167 (17)0.0316 (14)0.0145 (16)
C210.0603 (16)0.0617 (19)0.0639 (14)0.0040 (14)0.0043 (12)0.0023 (13)
C220.0536 (16)0.0608 (19)0.0442 (12)0.0012 (14)0.0162 (11)0.0003 (12)
C230.0726 (17)0.061 (2)0.0673 (16)0.0041 (17)0.0117 (13)0.0061 (14)
C240.100 (2)0.065 (2)0.0893 (19)0.0040 (19)0.0269 (18)0.0202 (16)
C250.081 (2)0.110 (3)0.0742 (19)0.019 (2)0.0162 (17)0.0368 (19)
C260.0629 (18)0.121 (3)0.0784 (19)0.003 (2)0.0059 (14)0.0256 (19)
C270.0598 (16)0.080 (2)0.0711 (15)0.0083 (16)0.0100 (14)0.0066 (14)
C280.0687 (17)0.086 (2)0.0927 (18)0.0024 (16)0.0318 (15)0.0313 (16)
Geometric parameters (Å, º) top
N1—C21.333 (2)C12—H120.9300
N1—C11.354 (2)C13—H13A0.9700
N2—C31.328 (2)C13—H13B0.9700
N2—C41.352 (2)C14—C151.394 (3)
N3—C71.374 (2)C14—C191.398 (3)
N3—C61.453 (2)C15—C161.376 (3)
N3—C51.463 (2)C15—H150.9300
N4—C221.415 (3)C16—C171.367 (4)
N4—C281.449 (3)C16—H160.9300
N4—C211.453 (3)C17—C181.376 (4)
N5—C141.376 (3)C17—H170.9300
N5—C131.449 (3)C18—C191.367 (4)
N5—C201.454 (3)C18—H180.9300
C1—C41.397 (3)C19—H190.9300
C1—C131.527 (3)C20—H20A0.9600
C2—C31.377 (2)C20—H20B0.9600
C2—C51.483 (3)C20—H20C0.9600
C3—C61.498 (3)C21—H21A0.9700
C4—C211.515 (3)C21—H21B0.9700
C5—H5A0.9700C22—C231.378 (3)
C5—H5B0.9700C22—C271.395 (3)
C6—H6A0.9700C23—C241.390 (3)
C6—H6B0.9700C23—H230.9300
C7—C81.392 (3)C24—C251.373 (4)
C7—C121.401 (3)C24—H240.9300
C8—C91.385 (3)C25—C261.366 (4)
C8—H80.9300C25—H250.9300
C9—C101.370 (3)C26—C271.378 (3)
C9—H90.9300C26—H260.9300
C10—C111.373 (3)C27—H270.9300
C10—H100.9300C28—H28A0.9600
C11—C121.380 (3)C28—H28B0.9600
C11—H110.9300C28—H28C0.9600
C2—N1—C1114.96 (16)C1—C13—H13B108.9
C3—N2—C4115.23 (17)H13A—C13—H13B107.7
C7—N3—C6122.57 (16)N5—C14—C15121.3 (2)
C7—N3—C5123.11 (17)N5—C14—C19121.3 (2)
C6—N3—C5113.64 (16)C15—C14—C19117.3 (3)
C22—N4—C28118.35 (19)C16—C15—C14120.9 (3)
C22—N4—C21117.9 (2)C16—C15—H15119.5
C28—N4—C21114.48 (18)C14—C15—H15119.5
C14—N5—C13120.75 (19)C17—C16—C15121.1 (3)
C14—N5—C20119.8 (2)C17—C16—H16119.4
C13—N5—C20117.9 (2)C15—C16—H16119.4
N1—C1—C4122.07 (18)C16—C17—C18118.5 (3)
N1—C1—C13115.34 (18)C16—C17—H17120.8
C4—C1—C13122.5 (2)C18—C17—H17120.8
N1—C2—C3122.80 (19)C19—C18—C17121.6 (3)
N1—C2—C5125.96 (18)C19—C18—H18119.2
C3—C2—C5111.24 (18)C17—C18—H18119.2
N2—C3—C2123.17 (19)C18—C19—C14120.6 (3)
N2—C3—C6126.31 (18)C18—C19—H19119.7
C2—C3—C6110.52 (19)C14—C19—H19119.7
N2—C4—C1121.65 (19)N5—C20—H20A109.5
N2—C4—C21115.81 (19)N5—C20—H20B109.5
C1—C4—C21122.52 (19)H20A—C20—H20B109.5
N3—C5—C2102.26 (16)N5—C20—H20C109.5
N3—C5—H5A111.3H20A—C20—H20C109.5
C2—C5—H5A111.3H20B—C20—H20C109.5
N3—C5—H5B111.3N4—C21—C4112.0 (2)
C2—C5—H5B111.3N4—C21—H21A109.2
H5A—C5—H5B109.2C4—C21—H21A109.2
N3—C6—C3102.22 (16)N4—C21—H21B109.2
N3—C6—H6A111.3C4—C21—H21B109.2
C3—C6—H6A111.3H21A—C21—H21B107.9
N3—C6—H6B111.3C23—C22—C27117.8 (2)
C3—C6—H6B111.3C23—C22—N4123.5 (2)
H6A—C6—H6B109.2C27—C22—N4118.7 (3)
N3—C7—C8121.19 (19)C22—C23—C24120.7 (3)
N3—C7—C12120.9 (2)C22—C23—H23119.6
C8—C7—C12117.9 (2)C24—C23—H23119.6
C9—C8—C7120.4 (2)C25—C24—C23121.0 (3)
C9—C8—H8119.8C25—C24—H24119.5
C7—C8—H8119.8C23—C24—H24119.5
C10—C9—C8121.2 (2)C26—C25—C24118.4 (3)
C10—C9—H9119.4C26—C25—H25120.8
C8—C9—H9119.4C24—C25—H25120.8
C9—C10—C11119.1 (2)C25—C26—C27121.5 (3)
C9—C10—H10120.4C25—C26—H26119.3
C11—C10—H10120.4C27—C26—H26119.3
C10—C11—C12120.8 (2)C26—C27—C22120.6 (3)
C10—C11—H11119.6C26—C27—H27119.7
C12—C11—H11119.6C22—C27—H27119.7
C11—C12—C7120.6 (2)N4—C28—H28A109.5
C11—C12—H12119.7N4—C28—H28B109.5
C7—C12—H12119.7H28A—C28—H28B109.5
N5—C13—C1113.53 (19)N4—C28—H28C109.5
N5—C13—H13A108.9H28A—C28—H28C109.5
C1—C13—H13A108.9H28B—C28—H28C109.5
N5—C13—H13B108.9
C2—N1—C1—C42.9 (3)N3—C7—C12—C11178.6 (2)
C2—N1—C1—C13180.0 (2)C8—C7—C12—C110.4 (3)
C1—N1—C2—C30.0 (3)C14—N5—C13—C175.0 (2)
C1—N1—C2—C5179.5 (2)C20—N5—C13—C191.0 (3)
C4—N2—C3—C22.3 (3)N1—C1—C13—N537.6 (3)
C4—N2—C3—C6178.1 (2)C4—C1—C13—N5145.3 (2)
N1—C2—C3—N22.8 (3)C13—N5—C14—C157.6 (3)
C5—C2—C3—N2177.7 (2)C20—N5—C14—C15173.29 (19)
N1—C2—C3—C6177.6 (2)C13—N5—C14—C19173.80 (19)
C5—C2—C3—C62.0 (3)C20—N5—C14—C198.1 (3)
C3—N2—C4—C10.6 (3)N5—C14—C15—C16178.5 (2)
C3—N2—C4—C21177.8 (2)C19—C14—C15—C160.2 (3)
N1—C1—C4—N23.4 (3)C14—C15—C16—C170.6 (4)
C13—C1—C4—N2179.8 (2)C15—C16—C17—C180.9 (4)
N1—C1—C4—C21174.9 (2)C16—C17—C18—C191.0 (4)
C13—C1—C4—C212.0 (3)C17—C18—C19—C140.7 (4)
C7—N3—C5—C2173.1 (2)N5—C14—C19—C18178.4 (2)
C6—N3—C5—C22.3 (2)C15—C14—C19—C180.3 (3)
N1—C2—C5—N3179.7 (2)C22—N4—C21—C4154.45 (18)
C3—C2—C5—N30.1 (2)C28—N4—C21—C459.3 (2)
C7—N3—C6—C3174.2 (2)N2—C4—C21—N4103.8 (2)
C5—N3—C6—C33.3 (2)C1—C4—C21—N477.8 (3)
N2—C3—C6—N3176.5 (2)C28—N4—C22—C23146.2 (2)
C2—C3—C6—N33.2 (2)C21—N4—C22—C231.2 (3)
C6—N3—C7—C8175.5 (2)C28—N4—C22—C2736.3 (3)
C5—N3—C7—C85.5 (3)C21—N4—C22—C27178.72 (19)
C6—N3—C7—C125.6 (3)C27—C22—C23—C241.6 (3)
C5—N3—C7—C12175.6 (2)N4—C22—C23—C24175.92 (19)
N3—C7—C8—C9178.8 (2)C22—C23—C24—C250.6 (4)
C12—C7—C8—C90.1 (3)C23—C24—C25—C260.8 (4)
C7—C8—C9—C100.2 (4)C24—C25—C26—C271.3 (4)
C8—C9—C10—C110.3 (4)C25—C26—C27—C220.3 (4)
C9—C10—C11—C120.1 (4)C23—C22—C27—C261.2 (3)
C10—C11—C12—C70.3 (4)N4—C22—C27—C26176.5 (2)
Hydrogen-bond geometry (Å, º) top
Cg2 and Cg3 are the centroids of rings N1/N2/C1–C4 and C7–C12, respectively.
D—H···AD—HH···AD···AD—H···A
C15—H15···N40.932.613.542 (3)175
C28—H28B···N20.962.593.323 (3)133
C6—H6B···Cg2i0.972.823.601 (2)138
C23—H23···Cg3i0.932.973.881 (3)168
Symmetry code: (i) x+1, y+2, z.
 

Acknowledgements

HSE is grateful to the University of Neuchâtel for their support over the years.

Funding information

Funding for this research was provided by: Swiss National Science Foundation, University of Neuchâtel.

References

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