부산대학교 도서관

We report the isolation of two unsymmetrical isomeric Schiff bases obtained from condensation of 2,4-pentanedione/1-phenyl-1,3-butanedione and 2-hydroxy-4-methoxyacetophenone/2-hydroxy-4-methoxybenzophenone with ethylenediamine and their VO(IV), Co(II), Ni(II), and Cu(II) complexes. Further reaction of each complex with triphenylphosphine resulted in formation of 1 : 1 adducts, with water occupying the sixth position in some, except copper and cobalt formed 1 : 2 adducts with [ML1]. The purities of the ligands and complexes were established by microanalyses and the complexes were characterized by magnetic susceptibility, conductance, infrared and electronic spectral measurements. The involvement of the azomethine N and phenolic O in bonding resulted in an N2O2 chromophore around the central metal atom. Infrared and electronic spectral data are consistent with square-planar/tetrahedral geometry for Ni(II), Co(II), and Cu(II) complexes and a five-coordinate, square-pyramidal geometry for the VO(IV) complexes. Evidence for triphenylphosphine adducts is adduced from microanalyses, spectral changes, and magnetic susceptibility measurements. [ABSTRACT FROM AUTHOR]