Protonation Reactions of trans-M(H)(SPh)(dppe)2 (M = Ru, Os) To Give Thiol and Dihydrogen Complexes. X-ray Crystal Structure Determination of trans-Ru(H)(SPh)(dppe)2 and trans-[Os(H)(O2)(dppe)2](O3SCF3)
journal contributionposted on 13.03.1998, 00:00 by Tanya Y. Bartucz, Adina Golombek, Alan J. Lough, Patricia A. Maltby, Robert H. Morris, Ravindranath Ramachandran, Marcel Schlaf
The compounds trans-M(H)(SPh)(dppe)2 (M = Ru (1Ru), Os (1Os); dppe = 1,2-bis(diphenylphosphino)ethane) are synthesized by reaction of NaSPh with trans-[Ru(H2)(H)(dppe)2]BPh4 or with trans-Os(H)(Br)(dppe)2 in THF under Ar. They are characterized by 1H and 31P NMR, IR, FAB mass spectroscopy, elemental analyses, and cyclic voltammetry. The crystal structure determination of 1Ru verifies the trans, octahedral geometry, which is distorted by ring−ring interactions. The thiophenoxide ligand is coordinated to the metal in a bent configuration, with the phenyl ring sandwiched between two phenyl rings of one of the dppe ligands. The reaction of complexes 1 with 1 equiv of HBF4·Et2O leads to the formation of the very reactive hydride thiol complexes trans-[M(H)(HSPh)(dppe)2]BF4 (M = Ru (2Ru), Os (2Os)). Analogous complexes to 1Os and 2Os with SC6H4-4-F instead of SPh are also described. In all cases there is no evidence for the existence of the tautomeric dihydrogen complex trans-[M(H2)(SAr)(dppe)2]+. In the presence of excess acid the diprotonated complex trans-[Os(H2)(HSPh)(dppe)2](BF4)2 (3Os) is formed at 233 K where the T1(min) of the H2 ligand at 400 MHz is ∼34 ms so that 0.98 ≤ dHH ≤ 1.24 Å. Under certain conditions the labile PhSH ligand of 3Os is substituted by water to give trans-[Os(H2)(OH2)(dppe)2](BF4)2 (4Os). The thiol complexes 2 react rapidly with H2(g) to give the complexes trans-[M(H2)H(dppe)2]BF4 (5Ru, 5Os). Complexes 3Os and 4Os also react with H2 to give 5Os. N2 and O2 (1 atm) displace the thiol in 2Os in CH2Cl2 to produce trans-[Os(H)(L)(dppe)2]+ (L = η1-N2 (6Os), η2-O2 (7Os)). trans-[Os(H)(O2)(dppe)2]OTf·3C6H6 is characterized by X-ray diffraction.