N. Benarous, Aouatef Cherouana, E. Aubert
Feb 5, 2016
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0
Influential Citations
16
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Journal
Journal of Molecular Structure
Abstract
Abstract Two new polymorphs of Schiff base, (E)-2-((2,6-dichlorobenzylidene)amino)benzonitrile, were prepared from the condensation of 4-amino-benzonitrile and 2,6-dichlorobenzaldehyde. The two polymorphs crystallize in two different space groups: P21/c for polymorph (I) with volume 1264.23(2) A3 and Pbca for polymorph (II) with volume 2469.3(2) A3. The two polymorphs have been characterized by FT-IR and UV-VIS spectroscopy. The crystal structures of both compounds were determined by single X-ray analysis. The difference between the two polymorphs was observed at the angle between the two phenyl rings which is 4.81° for the first one and 82.27° for the second one. Both crystal structures are built on the basis of moderate and weak hydrogen bonds. Theoretical calculations on isolated molecules at the MP2 cc-pVDZ level show that the two polymorphs correspond to two molecular conformations that are within less than 1 kJ mol−1 and DFT periodic calculations indicate that (II) is more stable than (I) by 4.1 kJ mol−1 of formula unit. Additionally, we performed TD-DFT calculation for free ligands to support the experimental data.