Studies on metal carboxylates. XV [1]. Solution reactions of rhodium(II) acetate with the gaseous hydrogen halides. The formation of complexes of rhodium(III)

Abstract

Rhodium(II) acetate, Rh 2(O 2CCH 3) 4, reacts with gaseous Hcl and HBr in acetone or ethanol to produce an insoluble residue of rhodium metal and solutions containing rhodium(III) which, upon treatment with Ph 4AsCl·nH 2O, produce the salts (Ph 4As)RhCl 4(H 2O) and (Ph 4As)RhBr 4(H 2O). These can in turm be used as starting materials for the synthesis of a variety of new rhodium(III) species. Complexes prepared in the present work are (Ph 4As)RhX 4(CH 3CN), RhX 3(PPh 3) 2(CH 3CN) and [RhX 2(LL) 2]X·2EtOH, where LL = 1,2-bis(diphenylphosphino)ethane and 1,2-bis(diphenylarsino)ethane. Details of their synthesis and spectral characterization are described. The X-ray photoelectron spectra (XPS) of [RhX 2(LL) 2]X·2EtOH show that the Cl 2p and Br 3p binding energies of the inner and outer sphere halogen environments differ by between 1.3 and 1.7 eV. The reactions of Rh 2(O 2CCH 3) 4 with HX(g) in non-aqueous media are contrasted with the corresponding reactions of the solid acetate with HX(g).