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)(O-2)(DPPE)(2)](O3SCF3)

The compounds trans-M(H)(SPh)(dppe)(2) (M = Ru (1Ru), Os (1Os); dppe = 1,2-bis(diphenylphosphino)ethane) are synthesized by reaction of NaSP h with trans-[Ru(H-2)(H)(dppe)(2)]BPh4 or with trans-Os(H)(Br)(dppe)2 in THF under Ar. They are characterized by H-1 and P-31 NMR, IR, FAB m ass spectroscopy, elemental analyses, and cyclic voltammetry. The crys tal structure determination of 1Ru verifies the trans, octahedral geom etry, which is distorted by ring-ring interactions. The thiophenoxide ligand is coordinated to the metal in a bent configuration, with the p henyl ring sandwiched between two phenyl rings of one of the dppe liga nds. 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 -F instead of SPh are also described. In al l cases there is no evidence for the existence of the tautomeric dihyd rogen complex trans-[M(H-2)(SAr)(dppe)(2)](+). Zn the presence of exce ss acid the diprotonated complex trans-[Os(H-2)(HSPh)-(dppe)(2)](BF4)( 2) (3Os) is formed at 233 K where the T-1(min) of the H-2 ligand at 40 0 MHz is similar to 34 ms so that 0.98 less than or equal to d(HH) les s than or equal to 1.24 Angstrom. Under certain conditions the labile PhSH ligand of 3Os is substituted by water to give trans[Os(H-2)(OH2)( dppe)(2)](BF4)2 (4OS). The thiol complexes 2 react rapidly with H-2(g) to give the complexes trans[M(H-2)H(dppe)(2)]BF4 (5Ru, 5Os). Complexe s 3Os and 4Os also react with H-2 to give 5Os. N-2 and O-2(1 atm) disp lace the thiol in 2Os in CH2Cl2 to produce trans-[Os(H)(L)(dppe)(2)]() (L eta(1)-N-2 (6Os), eta 2-O-2(7OS)). trans[Os(H)(O-2)(dppe)(2)]OTf . 3C(6)H(6) is characterized by X-ray diffraction.