The complex [Ru-2(mu-CO)(CO)(4)(mu-dppm)(2)] is more active than monon
uclear ruthenium complexes as a catalyst for decomposition of formic a
cid to CO2 and H-2; under conditions of highest activity, a coordinati
vely unsaturated diruthenium dihydride [Ru2H(mu-H)(mu-CO)(CO)(2)(mu-dp
pm)(2)] is present and can be isolated from solution.