Structure, physical, chemical and photophysical properties of Pt(bph) (CO) 2, where bph is the biphenyl dianion

Abstract

The complex Pt(bph) (CO) 2 crystallizes in the space group Cmcm with a = 18.647(6), b = 9.566(2) and c = 6.4060(5) A ̊ . The geometry of the molecule is slightly distorted from square planar with a PtC(CO) bond distance of 1.98(2) Å and a PtC(bph) bond distance of 2.04(2) Å. The Pt(bph)(CO) 2 complex serves as a precursor for the preparation of a wide variety of Pt(bph)X 2 complexes, where X = monodentate ligands such as acetonitrile, pyridine, etc., and X 2 = bidentate ligands such as bypyridine, 1,10-phenanthroline, etc. In the solid state, the complex exhibits a green color, but when ground with an alkali metal salt turns deep blue to purple. In CH 2Cl 2, the color disappears but optical transitions are observed at 271 nm (2.7 × 10 4 M −1 cm −1), 303 nm (1.1 × 10 4 M −1 cm −1) and 330 nm (5.5 × 10 3 M −1 cm −1). The complex is a weak emitter exhibiting a structured spectrum in CH 2Cl 2 at r.t. with maxima located at 562 and 594 nm and an emission lifetime of 3.1 μs when excited at 337 nm.