Conformational polymorphism of (<i>E</i>,<i>E</i>)-<i>N</i>,<i>N</i>′-bis(4-nitrobenzylidene)benzene-1,4-diamine
作者:Alain Collas、Matthias Zeller、Frank Blockhuys
DOI:10.1107/s0108270111010109
日期:2011.5.15
Two polymorphs of (E,E)‐N,N′‐bis(4‐nitrobenzylidene)benzene‐1,4‐diamine, C20H14N4O4, (I), have been identified. In each case, the molecule lies across a crystallographic inversion centre. The supramolecular structure of the first polymorph, (I‐1), features stacking based on π–π interactions assisted by weak hydrogen bonds involving the nitro groups. The second polymorph, (I‐2), displays a perpendicular
(E,E)-N,N'-双(4-硝基亚苄基)苯-1,4-二胺C 20 H 14 N 4 O 4(I)的两个多晶型物已被鉴定。在每种情况下,分子都跨过晶体学反转中心。第一个多晶型物(I-1)的超分子结构具有基于π-π相互作用的堆积,该相互作用由涉及硝基的弱氢键辅助。第二个多晶型物(I-2)显示通过硝基连接的分子的垂直排列,并带有弱的CHH ... O氢键。将两种晶体结构与碳类似物(E,E)-1,4-双[2-(4-硝基苯基)乙烯基]苯,(II)。