SYNTHESIS, STRUCTURES, SOLUTION BEHAVIOR, AND REACTIONS OF THIOLATO-BRIDGED DIRUTHENIUM CARBONYL PHOSPHINE COMPLEXES

Dinuclear thiolato-bridged complexes [Ru-2(CO)(4)(mu-SR)(2)(PR'(3))(2) ] (R' = Ph, Me) have been readily prepared from the reaction of [Ru-2( CO)(4)(MeCN)(4)(PR'(3))(2)][BF4](2) (R' = Ph (1), Me (2)) with RSH (R = Bu-t,Pr-i,Ph) and Et3N at ambient temperature. Although only the syn form of [Ru-2(CO)(4)(mu-(SBu)-Bu-t)(2)(PPh3)(2)] (3) and only the ant i form of [Ru-2(CO)(4)(mu-SPh)(2)(PMe3)(2)] (6) were found, an equilib rium mixture of both the syn (isomer A) and anti (isomer B) forms was present in solution for [Ru-2(CO)(4)(mu-(SPr)-Pr-i)(2)(PPh3)(2)] (4) a nd [Ru-2(CO)(4)(mu-SPh)(2)(PPh3)(2)] (5). The spectral data support th at the syn form (4A) is the major isomer of 4, while the anti form (5B ) is the major isomer of 5. The two thiolato bridges are located cis t o the two phosphine ligands in solid-state structures 3, 4A, and 5B, b ut they are located cis to only one of the two Ligands whereas they ar e trans to the other in structure 6. Iodination of 3-6 gave one identi cal product [Ru-2(CO)(4)(mu-SR)(2)I-2(PR'(3))(2)] (R' = Ph, R = Bu-t ( 7), Pr-t (8), Ph (9); R'=Me, R=Ph(10)). Both spectral and structural e vidence shows that 7-10 exist in the syn form with no Ru-Ru bonding in teraction The relative orientation of the two thiolato bridges with re spect to the two phosphine ligands present in 6 remains in structure 1 0, in spite of the change from anti to syn. The reactions of the diiod ide complexes [Ru-2(CO)(4)(mu-SR)(2)I-2(PR'(3))(2)] with R''S anions g ive either [Ru-2(CO)(4)(mu-SR)(2)(PR'(3))(2)] and R''SSR'' or [Ru-2-(C O)(4)(mu-SR)(2)(SR'')(2)(PR'(3))(2)].