Oxovanadium(IV) complexes of bromo and methoxy substituted N1,N4-diarylidene-S-methylthiosemicarbazones

Four new oxovanadium(IV) compounds were prepared by template reaction of salicyl-, 5-bromosalicyl- and 3-methoxysalicyl-aldehyde S-methylthiosemicarbazones with 2-hydroxy-, 5-bromo-2-hydroxy- and 3-methoxy-2-hydroxy-benzaldehyde in various combinations. The compounds were isolated as stable solid compounds with general formula [VO( L)] and characterized by elemental analysis, conductivity and magnetic measurements, electronic, IR and EPR spectroscopy. The X-band EPR signals recorded from powder forms of all samples have a single asymmetric line shape and theoretical fit studies proved the presence of axial symmetry around the paramagnetic vanadium ions. The anisotropic Lande splitting factors take values of g(parallel to) < g(perpendicular to) < g(c) = 2.0023. Orbital energy levels for magnetic electrons were determined from theoretically well fitted Spin Hamiltonian parameters. The EPR spectra recorded from solution forms almost have isotropic character. (C) Central European Science Journals Warsaw and Springer-Verlag Berlin Heidelberg. All rights reserved.