Rearrangement of the crystal structure during solid-phase elimination of solvate acetic acid from N'-(5-nitrofurfurylidene) isonicotinic hydrazide monohydrate

A new crystal modification of N'-(5-nitrofurfurylidene)isonicotinic hydrazide (1) was studied by IR spectroscopy and X-ray structural analysis. The compound studied is the product of solid-phase desolvation of solvate hydrate 1 of the composition [MeCOOH . 1 . H2O]. Spontaneous elimination of solvate acetic acid results in complex overall rearrangement of the crystal structure and formation of a new system of intermolecular hydrogen bonds. The crystal hydrate of 1:I composition (Ic) was formed from compound 1. In the crystal structure of Ic, molecules I are linked in infinite chains through intermolecular C=O...W...H-N hydrogen bonds. The second hydrogen atom of the molecule of the crystallization water is involved in formation of an intermolecular O-H...N(Py) hydrogen bond with the nitrogen atom of the pyridine ring of the molecule of the adjacent chain.