RuH2(H-2)(2)(PCy3)(2), the first reported stable bis (dihydrogen) complex c
rystallizes in the P1 space group; the two dihydrogen ligands lie in the eq
uatorial plane in a mutual cis position and are located trans to the hydrid
e ligands; the H-H distances are ca. 0.85 Angstrom, in agreement with the p
resence of unstretched dihydrogen ligands; these results are compared with
previous theoretical calculations using density functional theory.