A pyridine solution of [Pt(AuPPh3)8](NO3)2 showed surprisingly fast is
otope exchange catalysis between D2(gas) and H2O(liquid). Thus, H-2 an
d HD were produced with a turnover rate of ca. 1.5 min-1 from a pyridi
ne solution of cluster (1 x 10(-3) mmol), D2 (1.3 mmol), and H2O (0.6
mmol) at 1 atm and 30-degrees-C. There have been only a few reports of
this catalysis reaction with metal complexes, and the cluster gave a
rate at least 2 orders of magnitude faster. P-31 NMR of a pyridine sol
ution of [Pt(AuP-Ph3)8]2+ = M2+ under 0.1 atm of H-2 showed an equilib
rium mixture of M2+, M(H)2(2+), and a M(H)+ suggesting that the mechan
ism for exchange involved reversible deprotonation of M(H)2(2+) to giv
e M(H)+ and PyH+. The dihydrido cluster M(H)2(2+) is known to be in ra
pid equilibrium with M2+ and H-2.