Platinum(II) complexes with bidentate iminopyridine ligands: Synthesis, spectral characterization, properties and structural analysis

Four platinum(II) complexes, [PtCl2L] (L = (4-fluorophenyl)pyridin-2-ylmethylene-amine, 1; (4-chlorophenyl)pyridin-2-ylmethyleneamine, 2: (4-bromophenyl)pyridin-2-ylmethyleneamine, 3 and (4-iodophenyl)pyridin-2-ylmethyleneamine, 4) have been synthesized and characterized by CHN analysis, IR and UV-Vis spectroscopy. The crystal structures of 1 and 2 were determined using single crystal X-ray diffraction. The coordination polyhedron about the platinum (II) center in the complexes is best described as distorted square planar. The complexes undergo stacking to form a zigzag Pt center dot center dot center dot Pt center dot center dot center dot Pt chain containing both short (3.57(7) angstrom in 1 and 3.62(8) angstrom in 2) and long (5.16(7) angstrom in 1 and 5.41(9) angstrom in 2) Pt center dot center dot center dot Pt separations through the crystal. The compounds absorb moderately in the visible region, owing to a charge-transfer-to-diimine electronic transition. The redox potentials are approximately insensitive to the substituents on the phenyl ring of the ligands. (C) 2010 Elsevier Ltd. All rights reserved.