Oxovanadium(IV) complexes with unsymmetrical macrocyclic ligands derived from <i>o</i>-bromoaniline, <i>α </i>-or <i>β</i>-diketones and primary diamines
887-890A new series
of N4-donor unsymmetrical oxovanadium (IV) complexes of type [VO(mac)]SO4
(mac = macrocyclic ligands derived from o-bromoaniline, α -or β-diketones
and aliphatic diamines e.g. ethylenediamine or 1 ,3-propylenediamine ) have
been prepared by template synthesis. Tentative structures of the complexes have
been proposed on the basis of elemental analysis, electrical conductance, magnetic
moment and spectral (IR.
electronic and
EPR) data. The X-band EPR spectra of all the complexes have been recorded at
room temperature and at liquid N2 temperature. The room temperature EPR
spectra do not show anisotropy because of rapid tumbling of molecules in solution.
The spectral studies support square-pyramidal geometry for the vanadium(IV) complexes