4-Chloro-5-methyl-3-diphenylphosphino-1-phenyl-1,2,3,6-tetrahydrophosphinine as a bidentate P-ligand in a cis chelate Pt(II) complex

Double deoxygenation of a 3-phosphinoxido-1,2,3,6-tetrahydrophosphine oxide (2) led to bisphosphine 3–2 with an inverted ring P atom. The reaction of bidentate P-ligand 3–2 with dichlorodibenzonitrilo platinum(II) yielded the mixture of a novel cis chelate complex (7 = PtCl2(3–2)) and a cis bis(3-diphenylphosphino-1,2,3,6-tetrahydrophosphininyl) complex (8 = PtCl2(η1-5)2) containing two units of monodentate P-ligand 5.