Dwivedi Bhavna, Das Dinabandhu
School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110 067, India.
Acta Crystallogr C Struct Chem. 2018 Dec 1;74(Pt 12):1656-1666. doi: 10.1107/S2053229618014286. Epub 2018 Nov 15.
We describe the polymorphism of four new bis-hydrazone compounds, namely butane-2,3-dione 2,3-bis{[bis(4-fluorophenyl)methylidene]hydrazone}, CHFN (1), butane-2,3-dione 2,3-bis{[bis(4-chlorophenyl)methylidene]hydrazone}, CHClN (2), butane-2,3-dione 2,3-bis{[bis(4-methylphenyl)methylidene]hydrazone}, CHN (3), and butane-2,3-dione 2,3-bis({bis[4-(dimethylamino)phenyl]methylidene}hydrazone), CHN (4), derived by the condensation reaction between substituted benzophenone hydrazone and butane-2,3-dione. Concomitant polymorphism has been observed in 1, 2 and 3. Overlays of molecules of the different polymorphs indicate that there is conformational adjustment in the crystal structures of the polymorphs of 1 and 2, i.e. packing polymorphism, which was confirmed by a computational study. On the other hand, conformational change was observed in the cases of the polymorphs of compounds 3 and 4, i.e. conformational polymorphism.
我们描述了四种新型双腙化合物的多晶型现象，即丁二酮2,3 - 双{[双(4 - 氟苯基)亚甲基]腙}，CHFN (1)；丁二酮2,3 - 双{[双(4 - 氯苯基)亚甲基]腙}，CHClN (2)；丁二酮2,3 - 双{[双(4 - 甲基苯基)亚甲基]腙}，CHN (3)；以及丁二酮2,3 - 双({双[4 - (二甲氨基)苯基]亚甲基}腙)，CHN (4)，这些化合物是由取代二苯甲酮腙与丁二酮之间的缩合反应得到的。在1、2和3中观察到了伴随的多晶型现象。不同多晶型分子的叠加表明，1和2的多晶型晶体结构中存在构象调整，即堆积多晶型，这一点通过计算研究得到了证实。另一方面，在化合物3和4的多晶型情况下观察到了构象变化，即构象多晶型。
