The complex Pt(SnBu3t)(2)(CNBut)(2)(H)(2), 1, was obtained from the reaction of Pt(COD)(2) and (Bu3SnH)-Sn-t, followed by addition of CNBut. The two hydride ligands in 1 can be eliminated, both in solution and in the solid state, to yield Pt(SnBut(3))(2)(CNBut)(2), 2. Addition of hydrogen to 2 at room temperature in solution and in the solid state regenerates 1. Complex 2 catalyzes H-2-D-2 exchange in solution to give HD. The proposed mechanism of exchange involves reductive elimination of (Bu3SnH)-Sn-t from 1 to afford vacant sites on the Pt center, thus facilitating the exchange process. This is supported by isolation and characterization of Pt(SnMes3)(SnBu3t)(CNBut)(2), 3, when the addition of H-2 to 2 was carried out in the presence of free ligand Mes3SnH (Mes = 2,4,6-Me3C6H2). Complex Pt(SnMes(3))(2)(CNBut)(2), 5, can be prepared from the reaction of Pt(COD)2 with Mes(3)SnH and CNBut. The exchange reaction of 2 with Ph3SnH gave Pt(SnPh3)(3)(CNBut)(2)(H), 6, wherein both SnBu3t ligands are replaced by SnPh3. Complex 6 decomposes in air to form square planar Pt(SnPh3)(2)(CNBut)(2), 7. The complex Pt(SnPr3i)2(CNBut)(2), 8, was also prepared. Out of the four analogous complexes Pt(SnR3)(2)(CNBut)(2) (R = Bu-t, Mes, Ph, or Pri), only the But analogue does both H-2 activation and H-2-D-2 exchange. This is due to steric effects imparted by the bulky Bu-t groups that distort the geometry of the complex considerably from planarity. The reaction of Pt(COD)(2) with (Bu3SnH)-Sn-t and CO gas afforded trans-Pt(SnBu3t)(2)(CO)2, 9. Compound 9 can be converted to 2 by replacement of the CO ligands with CNBut via the intermediate Pt(SnBut(3))(2)(CNBut)(2)(CO), 10.