Sulfur chelates. 32. Studies of the solid-state molecular structure and solution structures and dynamics of bis(phosphine) adducts of platinum(II) 1,1-dithiolates. Molecular structures of Pt[S2CN(i-Bu)2]2(PMe2Ph)2, Pt(S2CO)(PPh3)2, and Pt(S2CO)(diphos).14CHCl3