POLYOXOANION-SUPPORTED METAL-CARBONYLS - SYNTHESIS AND CHARACTERIZATION OF ([(OC)2RH]5(NB2W4O19)2)3-, ([(OC)2RH]3(NB2W4O19)2)5-, ([(OC)2IR]2H(NB2W4O19)2)5-, AND [(OC)2IR(P3O9)]2-

The first polyoxyanion-supported rhodium and iridium carbonyl complexes have been prepared as (n-C4H9)4N+ or [(C6H5)3P]2N+ salts and assigned structures similar to those of known rhodium and iridium diene complexes by using multinuclear (17O, 13C, 183W, and/or 31P) NMR and IR spectroscopy. Reaction of either |[(C7H8)Rh]5(Nb2W4O19)2}[(n-C4H9)4N]3 with CO in nitromethane solution or Nb2W4O19[(n-C4H9)4N]4 with [(OC)2RhCl]2 in 1,2-dichloroethane solution yields crystalline {[(OC)2Rh]5(Nb2W4O19)2}[(n-C4H9)4N]3 (1) in 75% yield. The anion of 1 has a structure derived from its (norbornadiene)rhodium precursor by replacement of each C7H8 ligand by two CO ligands: two octahedral Nb2W4O194− anions are linked together face-to-face by five (OC)2Rh+ units. Reaction of Nb2W4O19[(n-C4H9)4N]4 with [(OC)2RhCl]2 in chloroform yields {[(OC)2Rh]3(Nb2W4O}9)2)[(n-C4H9)4N]5 (2) in 41% yield. The structure proposed for the anion of 2 is obtained by removing two (OC)2Rh+ units from the structure of the anion of 1, specifically, those bonded to ONbW oxygens. Bubbling CO through a CH3CN solution of ([(C8H12Ir]2H(Nb2W4O19)2}[n-C4H9)4N]5 yields {[(OC)2Ir]2H(Nb2W4O19)2}[(n-C4H9)4N]5 (3) in >80% yield. The anion of 3 is proposed to have a structure derived from the structure of its (cyclooctadiene)iridium precursor by replacement of each CgH12 ligand with two CO ligands. In this structure, two octahedral Nb2W4O194− anions are linked together edge-to-edge by a proton and two (OC)2Ir+ cations. The trimetaphosphate complex [(OC)2Ir(P3O9)]{[(C6H5)3P]2N}2 (4) is prepared by substitution of cycloctadiene ligands in [(C8H12)Ir(PO9)]{[(C6H5)3P]2N}2 with CO ligands. As was the case with compounds 1 and 3, the anion of 4 is proposed to have a structure derived from the diene precursor structure by replacement of each diene ligand with two CO ligands, yielding a square-pyramidal Ir(I) complex having two basal CO ligands and a k3O-P3O93− ligand spanning two adjacent basal and the apical sites. © 1990, American Chemical Society. All rights reserved.