Rhodium complexes of diphenylphosphino(ethylthio)ethane

Abstract

The dimeric complex, [(OC)₂Rh(μ-Cl)₂ Rh(CO)₂], undergoes bridge splitting reaction with Ph₂PCH₂CH₂SEt (P-S) to produce the chelated complex, [Rh(CO)Cl(P_∩S)](<b>1</b>) (P_∩S =η²

- coordinated P-S ), which on oxidative addition with MeI and I₂ yields [Rh(COMe)ICl(P_∩ S)](<b>2</b>) and [Rh(CO)I₂Cl(_∩)](<b>3</b>) respectively. On the other hand , the bridge splitting reaction of the dimeric complex, [(COD)Rh(μ-Cl)₂ Rh(COD)] (COD =1,5- cyclooctadiene), with P-S produces a non-chelated complex, [Rh(COD)Cl(P~S)](<b>4</b>) (P-S =η¹-coordinated P-S). All the complexes have been characterized by elemental analyses, IR, ¹ H and ³¹P{<b>¹</b>H} NMR spectroscopy. The catalytic activity of the complexes <b>1</b> and <b>4</b> for carbonylation of methanol is found to be higher than that of the well known species, [Rh(CO)₂I₂].