Trinuclear Pyrazolate Complexes - Crystal-Structure Of [(Oc)2rh(Mu-Pz)2pd(Mu-Pz)2rh(Co)2]

The preparation and properties of trinuclear complexes containing pyrazolate and chloride as bridging ligands are reported. Representative formulae are [L2M(µ-Cl)(µ-pz)Pd(µ-Cl)(µ-pz)ML2][M = Rh, L2= diolefin or (CO)2; M = Ir, L2= diolefin; M = Pd, L2=η3-C3H5 or η3-C4H7]. These complexes react with the pyrazolate anion to give trinuclear homobridged compounds of formula [L2M(µ-pz)2Pd(µ-pz)2ML2]. The crystal structure of the carbonyl derivative [(OC)2Rh(µ-pz)2Pd(µ-pz)2Rh(CO)2] has been determined by single-crystal X-ray methods. Crystal are monoclinic, space group P21/c with cell constants a= 8.9281(5), b= 11.7961(6), c= 10.391 6(5)A, β= 94.727(4)°, and Z= 2. The intermetallic distance palladium–rhodium is equal to 3.578 9(6)A.