Reactivity of rhodium(III) complexes containing chelating pentachlorophenyl ligands. Molecular structures of fac-[Rh(C6Cl5)(3)(py)] and mer-[Rh(C6Cl5)(3)((BuNC)-Bu-t)(3)]
Mp. Garcia et al., Reactivity of rhodium(III) complexes containing chelating pentachlorophenyl ligands. Molecular structures of fac-[Rh(C6Cl5)(3)(py)] and mer-[Rh(C6Cl5)(3)((BuNC)-Bu-t)(3)], INORG CHIM, 308(1-2), 2000, pp. 51-58
The reactions of the octahedral rhodium(III) complexes [Rh(C6Cl5)(3)] and [
Rh(C6Cl5)(3)CI](-) with neutral monodentate ligands have been studied. With
pyridine, triethylphosphine or pyrazole, one of the rhodium-o-chloro bonds
of the starting materials is broken and complexes of formula [Rh(C6Cl5)(3)
L] and [Rh(C6Cl5)(3)CIL](-) are obtained. Carbonylation of [Rh(C6Cl5)(3)] p
roduces the insertion of CO molecules in two of the Rh-C-aryl bonds giving
the diacyl complex [Rh{C(O)C6Cl5}(2)(C6Cl5)(CO)], while the reaction of [Rh
(C6Cl5)(3)] or [Rh(C6Cl5)(3)Cl](-) with the strong sigma -donor ligand 'BuN
C breaks all the rhodium-o-chloro interactions producing the compound mer-[
Rh(C6Cl5)(3)('BuNC)(3)]. All the complexes are stable to the air and moistu
re in the solid state and moderately stable in deoxygenated solutions. The
compounds have been studied and characterised by IR, NMR and MS. The crysta
l structures of fac-[Rh(C6Cl5)(3)(py)] and mer-[Rh(C6Cl5)(3)('BuNC)(3)] hav
e been determined by X-ray diffraction methods. They display distorted octa
hedral metal environments but, while the pyridine complex shows two C6Cl5 g
roups acting as chelate ligands bonded through the ipso-C atom and one of t
he o-Cl atoms, the isocyanide complex exhibits all the coordinated ligands
acting as monodentate groups. (C) 2000 Elsevier Science S.A. All rights res
erved.