Isomorphism in Two (E)-1-(4-Halophenyl)-N-[1-(4-Methylphenyl)-1H-Imidazol-4-yl]Methanimines (Halide = Cl, Br)
作者:Hanna Skrzypiec、Radosław Mazurek、Paweł Wagner、Maciej Kubicki
DOI:10.1007/s10870-012-0354-1
日期:2012.10
The crystal structures of two imidazole-4-imines, (E)-1-(4-chlorophenyl)-N-[1-(4-methylphenyl)-1H-imidazol-4-yl]methanimine (1, C17H14ClN3), and (E)-1-(4-bromophenyl)-N-[1-(4-methylphenyl)-1H-imidazol-4-yl]methanimine, (2, C17H14BrN3), are isomorphous, the isostructurality index is 99.4 %. Both compounds crystallize in the triclinic space group P-1 with unit cell parameters at 100(1) K as follows: for (1), a = 7.9767(5) Å, b = 10.9517(7) Å, c = 16.6753(12) Å, α = 80.522(6)°, β = 87.046(6)°, γ = 89.207(5)°, and for (2), a = 8.0720(7) Å, b = 10.9334(10) Å, c = 16.8433(13) Å, α = 81.161(7)°, β = 86.605(7)°, γ = 89.505(7)°. The structures contain two symmetry—independent but conformationally similar molecules in the asymmetric unit (Z’ = 2). In both compounds the overall twist of the molecule, defined as the dihedral angle between the terminal phenyl ring planes is significant, around 56°. The crystal packing is determined mainly be weak specific intermolecular interactions: the C–H···N hydrogen bonds connect molecules into infinite chains, and the chains are linked via C–H···X hydrogen bonds and by π–π interactions. This study illustrates the significant role of the weak interactions, which—in spite of their weakness—can robustly repeat in the crystal structures of similar compounds. Two imidazole-4-imines, (E)-1-(4-chlorophenyl)-N-[1-(4-methylphenyl)-1H-imidazol-4-yl]methanimine, and (E)-1-(4-bromophenyl)-N-[1-(4-methylphenyl)-1H-imidazol-4-yl]methanimine, are isomorphous, the isostructurality index is 99.4 %.
两种咪唑-4-亚胺,(E)-1-(4-氯苯基)-N-[1-(4-甲基苯基)-1H-咪唑-4-基]甲亚胺(1,C17H14ClN3)的晶体结构、和(E)-1-(4-溴苯基)-N-[1-(4-甲基苯基)-1H-咪唑-4-基]甲亚胺(2,C17H14BrN3)同构,同构指数为 99.4 %。这两种化合物都在三菱空间群 P-1 中结晶,在 100(1) K 时的单胞参数如下:对于 (1),a = 7.9767(5) Å, b = 10.9517(7) Å, c = 16.6753(12) Å, α = 80.522(6)°, β = 87.046(6)°, γ = 89.207(5)°, 对于 (2), a = 8.0720(7) Å, b = 10.9334(10) Å, c = 16.8433(13) Å, α = 81.161(7)°, β = 86.605(7)°, γ = 89.505(7)°.这些结构在不对称单元(Z' = 2)中包含两个对称性无关但构象相似的分子。在这两种化合物中,分子的整体扭转(定义为末端苯环平面之间的二面角)非常明显,约为 56°。晶体堆积主要是由微弱的特定分子间相互作用决定的:C-H--N 氢键将分子连接成无限的链,链之间通过 C-H--X 氢键和 π-π 相互作用连接。这项研究说明了弱相互作用的重要作用,尽管它们很微弱,但却能在类似化合物的晶体结构中有力地重复出现。两种咪唑-4-亚胺--(E)-1-(4-氯苯基)-N-[1-(4-甲基苯基)-1H-咪唑-4-基]甲亚胺和(E)-1-(4-溴苯基)-N-[1-(4-甲基苯基)-1H-咪唑-4-基]甲亚胺是同构的,同构指数为 99.4 %。