Homo- and hetero-binuclear complexes containing the anion [Rh(C5Me5){PO(OMe)2}2(pyrazolate)]–as ligand. Crystal structure of [(C5Me5)Rh{µ-PO(OMe)2}2(µ-C3H3N2)-Ru(C6H6)]ClO4·CH2Cl2

Abstract

The neutral rhodium(III) complex [Rh(C5Me5)I{PO(OMe)2}{P(OH)(OMe)2}] reacts with pyrazole-type ligands [HL = pyrazole (Hpz), 3-methylpyrazole, or 3,5-dimethylpyrazole] in the presence of AgClO4 yielding cationic complexes of the general formula [Rh(C5Me5){PO(OMe)2}{P(OH)(OMe)2}(HL)]ClO4. They react with Na2CO3 in aqueous solutions with formation of the neutral complexes [Rh(C5Me5){PO(OMe)2}2(HL)]. Addition of NaH in tetrahydrofuran to the cationic complexes or thallium acetylacetonate in MeOH to the neutral compounds affords the corresponding bimetallic derivatives [(C5Me5)Rh{PO(OMe)2}2LM](M = Na or Tl). These complexes react with halide compounds such as [{M(ring)Cl2}2][M(ring)= Rh(C5Me5), Ir(C5Me5), Ru(C6H6), Ru(C6H5Me), Ru(MeC6H4Pri-p) or Ru(C6Me6)], [MBr(CO)5], [(PtMe3I)4] or [{Rh(µ–Cl)(cod)}2](cod = cycloocta-1,5-diene) to give cationic or netural complexes of the type [(C5Me5)Rh{µ-PO(OMe)2}2(µ-L)-M(ring)]ClO4 or [(C5Me5)Rh{PO(OMe)2}2(µ-L)MLn][MLn= Re(CO)3, Mn(CO)3, PtMe3 or Rh(cod)]. The crystal structure of [(C5Me5)Rh{µ-PO(OMe)2}2(µ-pz)Ru(C6H6)]ClO4·CH2Cl2 has been determined by X-ray diffraction methods: monoclinic, space group P21/c, a= 11.179(1), b= 17.039(1), c= 18.186(2)A, β= 94.85(1)° and Z= 4. The complex cation consists of one rhodium and one ruthenium atom bridged by two phosphonate and one pyrazolate anion. An η5-C5Me5 and an η6-C6Me6 group complete the co-ordination spheres of the metals, which show no direct intermetallic interaction.