Synthesis of the homoleptic rhodium(III) complex [Rh(C6Cl5)(3)]. Molecularstructures of [Rh(C6Cl5)(3)] and [Rh(C6Cl4-C6Cl4)(C6Cl5)-(SC4H8)(2)]

The arylation of[RhCl3(SC4H8)(3)] (SC4H8 = tetrahydrothiophene, tht) with t he Grignard reagent MgCl(C6Cl5), under different reaction conditions, affor ded the neutral rhodium(III) complexes [Rh(C6Cl5)(3)] 1 and [Rh(C6Cl4- C6Cl 4)(C6Cl5)(tht)(2)] 2 as well as the paramagnetic rhodium(II) compound [Rh(C 6Cl5)(2)(tht)(2)] 3. The homoleptic complex 1 can also be obtained by treat ment of [P(CH2Ph)Ph-3][RhCl(C6Cl5)(3)] with AgClO4. The complexes are stabl e to the air and moisture in the solid state and moderately stable in deoxy genated solutions. The crystal structures of compounds 1 and 2 have been de termined. They display distorted octahedral environments. All C6Cl5 groups in 1 or one C6Cl5 group in 2 act as chelating ligands being bonded through the ipso-C atom and one of the ortho-Cl atoms. Complex 2 additionally incor porates two tetrahydrothiophene ligands and a perchloro-2,2'-biphenylene li gand, formed by coupling of two pentachlorophenyl groups.