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

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) Angstrom. The geometry of the molecule is slightly distorted from square planar with a Pt-C(CO) bond distance of 1.98(2) Angstrom and a Pt-C(bph) bond distance of 2.04(2) Angstrom. 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 CH2Cl2, the color disappears but optical transitions are observed at 271 nm (2.7 X 10(4) M(-1) cm(-1)), 280 nm (4.6 X 10(4) M(-1) cm(-1)), 303 nm (1.1 X 10(4) M(-1) cm(-1)) and 330 nm (5.5 X 10(3) M(-1) cm(-1)). The complex is a weak emitter exhibiting a structured spectrum in CH2Cl2 at r.t. with maxima located at 562 and 594 nm and an emission lifetime of 3.1 mu s when excited at 337 nm.