Synthesis and Structures of Dinuclear 3,5-Bis(trifluoromethyl)pyrazolate Complexes of Ruthenium.

Reaction of 3,5-(CF 3) 2PzLi with [Cp*RuCl 2] n(2:1) in diethyl ether at −78 °C gives [(Cp*RuLi) 2(μ 4-O)(μ 2-Cl)(μ-3,5-(CF 3) 2Pz) 3] ( 1) in 75% yield [3,5-(CF 3) 2Pz = 3,5-bis(trifluoromethyl)pyrazolate]. With a 1:1 ratio of [Cp*RuCl 2] nto 3,5-(CF 3) 2PzLi, dark-green crystalline [Cp*Ru(μ-Cl)] 2(μ-3,5-(CF 3) 2Pz) ( 2) is produced in ca. 50% yield. The reaction of 3,5-(CF 3) 2PzLi with [RuCl 2(1,4-Me,iPrC 6H 4)] 2in diethyl ether at −78 °C gives the chloride-bridged dimer [RuCl(η 6-1,4-Me,iPrC 6H 4)(μ-3,5-(CF 3) 2Pz)] 2( 3) in 65% yield. The reaction of Cp*Ru(OSO 2CF 3) 2with 3,5-(CF 3) 2PzLi (2:1) in diethyl ether at −78 °C produced the unusual dinuclear Ru III−Ru IIIcomplex [Cp*Ru(μ-O)(μ-η 5,η 1-C 5Me 4CH 2)Ru(η 1-3,5-(CF 3) 2Pz)]·0.25Et 2O ( 4) in 75% yield. Complexes 1– 4have been characterized spectroscopically and by single-crystal X-ray diffraction studies. [ABSTRACT FROM AUTHOR]