Secondary phosphine chalcogenides. 6. Some reactions of dipalladium(I) and diplatinum(I) complexes of the type [M2(.mu.-SPR'2)2(PR3)2] (M = Pd, Pt; R,R' = alkyl, aryl). Crystal and molecular structure of [Pd2(.mu.-SPPh2)2(CNMe)2].CHCl3