Cocrystallization of two isomers of N′-(5-nitrofurfurylidene)benzhydrazide and features of the molecular,crystal, and electronic structure of their crystal hydrate

1.

An x-ray diffraction structural study of crystals of N-(5-nitrofurfurylidene)benzhydrazide revealed the first case of the cocrystallization of syn and syn-anti isomers of ketohydrazone molecules. We propose that the isomerization of the ketohydrazone molecules occurs upon crystallization and is a consequence of packing effects. The crystal structure of this ketohydrazone is a rare case of the laminar packing of polar and nonpolar molecular chains.

2.

The formation of hydrates of N-(5-nitrofurfurylidene)hydrazides radically alters the structure of their frontier molecular orbitals in comparison with the anhydrous molecules. This may significantly affect the properties of the crystals of these compounds.

Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2301–2308, October, 1988.