Gas-phase reactivities of charged platinum dimers with ammonia: A combined experimental/theoretical study

Computational and experimental studies of Pt 2 ± with ammonia are reported. While ammonia is dehydrogenated with either cluster type, the reaction efficiencies ϕ are quite different with ϕ = 0.27 for Pt 2 + / NH 3 [K. Koszinowski, D. Schröder, H. Schwarz, J. Phys. Chem. A 107 (2003) 4999.] and ϕ = 0.0033 for Pt 2 - / NH 3 . DFT-based relativistic calculations are consistent with this distinct behavior, with maximum energies along the reaction path of −13.3 kcal/mol for the cationic and +1.4 kcal/mol for the anionic clusters relative to the reactants. The recently proposed mechanism for the Pt 2 + / NH 3 system [D. Xu. X.-Y. Chen, S.-G. Wang, Int, J. Quant. Chem. 107 (2007) 1985.] needs to be modified to account for the experimental findings.