Evaluation of vanadium coordination compounds derived from simple acetic acid hydrazide as non-conventional semiconductors

Abstract

Vanadium hydrazone complexes were prepared by the reaction of [VO(C₅H₇O₂)₂] and NH₄VO₃ with hydrazone ligands. The ligands were prepared by the reaction of acetic acid hydrazide with 2-hydroxy-5-nitrobenzaldehyde (H₂L¹), 2-hydroxybenzaldehyde (H₂L²), or 2-hydroxy-3-methoxybenzaldehyde (H₂L³). Mononuclear and dinuclear vanadium(V) complexes were characterized by spectroscopic methods and elemental analysis, while their thermal behaviour was examined by thermogravimetry and temperature-dependent powder X-ray diffraction. The structural transformations of specific complexes were observed by applying the in situ solid-state impedance spectroscopy (SS-IS) technique, and their electrical characteristics were systematically correlated with their thermal and structural properties. Crystal and molecular structures of complexes (NH₄)[VO₂(L¹)], [VO(L¹)(OMe)(MeOH)], [VO(L²)(OMe)(MeOH)]·MeOH, [VO(L³)(OMe)(MeOH)], [VO(L³)(OEt)(H₂O)], and [VO₂(HL³)]₂·2H₂O, were determined by single crystal X-ray diffraction and their optical properties were assessed using UV-Vis diffuse reflectance spectroscopy.