Trifluoroacetonitrile displaces trans-stilbene from Pt(trans-stilbene)(PPh3)2 to give Pt(π-CF3CN)(PPh3)2, (I). The trifluoroacetonitrile ligand in (I) is labile and is displaced by diphenylacetylene and carbon monoxide to give Pt(PhCCPh)(PPh3)2 and Pt3(CO)3(PPh3)4 respectively. Other displacement reactions indicate that the complexes Pt(L)(PPh3)2 decrease in stability in the order of ligands (L), (CF3)2CO > PhCCPh > CF3CN > CF2 CH2 > trans-PhCHCHPh. In addition to Pt{(CF3)2CO}(PPh3)2, a five-membered ring complex (Ph3P)2P[graphic omitted] may also be isolated from the reaction of (I) with hexafluoroacetone. Treatment of (I) with trifluoroacetic acid gives a mixture of trans-PtH(OCOCF3)(PPh3)2 and trans-Pt(OCOCF3)-{C(CF3)NH}(PPh3)2.