First crystallographic investigation of complexes of cis-VO₂⁺, cis-MoO₂²⁺, and trans-UO₂²⁺ species with Schiff-base molecules derived from 4,6-O-ethylidene-β-D-glucopyranosylamine

Abstract

The interaction of Schiff-base ligands derived from 4,6-O-ethylidene-β-D-glucopyranosylamine with cis-VO₂⁺, cis-MoO₂²⁺, and trans-UO₂²⁺ species have been studied by isolating and characterizing the corresponding products. The structures of one complex of each type of species have been established by single-crystal X-ray diffraction analysis. In all the complexes, the saccharide moiety adopts a chair conformation and has a β-anomeric form. A gradual increase in coordination number (5, 6, and 7) and a gradual variation in the geometry (distorted trigonal-bipyramidal, distorted octahedral, and pentagonal-bipyramidal) are observed on going from the complexes of cis-VO₂⁺ (mononuclear) to cis-MoO₂²⁺ (mononuclear) to trans-UO₂²⁺ (dinuclear). A variation in the binding mode of the ligand towards these dioxometal species is also observed. Intermolecular interactions of the type O-H···O, C-H···O, and N-H···O present in the lattices of these complexes lead to the formation of interesting structures.