(Indenyl)ruthenium Complexes Containing 1,1′‐Bis(diphenylphosphanyl)ferrocene (dppf) and Thiolato Ligands: Synthesis, X‐ray Structure Analysis, Electrochemistry and Magnetic Studies

The reaction of [(Ind)Ru(dppf)Cl] (Ind = η 5 ‐C 9 H 7 ) ( 2 ) with RSNa {R = Me, Et, Ph, Ph 2 P(CH 2 ) 2 } proceeds in MeOH to give [(Ind)Ru(dppf)(SR)] {R = Me ( 3 ), Et ( 4 ), Ph ( 5 ), Ph 2 P(CH 2 ) 2 ( 7 )}, as well as [(Ind)Ru(dppf)H] ( 6 ), in all cases except for R = Ph. This R‐dependence of the product mixture was rationalised on a RS – /MeOH ↔ MeO – /RSH equilibrium involving the interaction of thiolate (RS – ) with MeOH, and the relative nucleophilicities of RS – versus MeO – ; 6 arose from β‐H elimination from an OMe derivative. Cyclic voltammetric measurements on 2 , 3 , 4 and 5 , as well as the Cp (η 5 ‐C 5 H 5 ) and Cp* (η 5 ‐C 5 Me 5 ) analogues of 2 , indicated that the formal oxidation potentials for [LRu(dppf)Cl] complexes {L = Ind ( 2 ), Cp ( 2A ) and Cp* ( 2B )} occurred in the order Cp* < Ind < Cp, correlating with the more electron‐donating groups lowering the oxidation potentials. EPR experiments performed on the one‐electron oxidised forms of 3 and 5 indicated paramagnetic compounds with g values close to 2, while the two‐electron oxidised forms of 3 and 5 were diamagnetic. All the complexes were characterised spectroscopically, and 5 and 6 also crystallographically. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)