Synthesis and vibrational study of platinum(II) and palladium(II) complexes of glyoxilic acid oxime

New platinum(II) and palladium(II) complexes of glyoxilic acid oxime (gao) have been prepared and characterised by infrared (4000-150 cm(-1)) and Rama n (4000-200 cm(-1)) spectra. The gao acts as bidentate ligand bonding throu gh the oxime nitrogen and carboxyl oxygen atoms to form neutral bis-chelate square-planar complexes. The lowest energy conformer of the gao ligand (ec tt) was selected among 16 theoretically possible conformers on the basis of ab initio calculations at HF/3-21G*, HF/6-31G* and HF/6-311** levels of th e theory from which structural parameters and conformational stabilities ha ve been obtained. A complete vibrational assignment of the gao was performe d for the lowest energy ectt conformer on the basis of ab initio optimised parameters and normal coordinate analysis calculations (PED). NCA calculati ons of the complexes studied were also performed. (C) 1999 Elsevier Science B.V. All rights reserved.