Polynuclear oxovanadium(IV) Schiff base complex [VOL2]_n (L = (5-bromo-2-hydroxybenzyl-2-furylmethyl)imine): Synthesis, characterization, crystal structure, catalytic properties and thermal decomposition into V2O5 nano-particles

摘要

Polynuclear oxovanadium(IV) Schiff base complex [V0L2]_n of bidentate NO Schiff base ligand (L = 5-bromo-2-hydroxybenzyl-2-furyl(methyl)imine) was synthesized and characterized by elemental analysis and FT-IR spectroscopy. The crystal structure of [VOL2]_n has been determined by single crystal X-ray diffraction. The complex has two symmetry independent vanadium centers located on a two-fold axis. Both centers have a distorted octahedral N2O4 coordination sphere. Two Schiff base ligands act as chelating ligands and coordinate to the vanadium center each via one nitrogen and one oxygen atom. The remaining two apices of the octahedron are occupied by oxygen shared by the neighboring vanadium atoms, giving rise to ID coordination polymer [VOL2]_n with the interatomic V···V distance 3.7670(6) A. This complex is used as a catalyst for the epoxidation of the cyclooctene. Different reaction parameters were optimized and the results showed that it can be active and selective in the optimized conditions. After thermal decomposition of the complex, the XRD pattern of the obtained solid shows the formation of the V2O5 nano particles with the average size of 41 nm.