Pentamethylcyclopentadienyliridium(III) complexes containing tertiary phosphorus chalcogenide ligands: Crystal structure of [(η5C5Me5)Ir{PO(OMe)2}{η2(SPPh2)2CH2-S,S′}]BF4 · 0.5Me2CO

Article abstract of DOI:10.1016/0022-328X(95)05909-9

Neutral iridium(III) complexes of the unidentate P-donor ligands dppm, dppmS and dppmSe, and cationic complexes with these ligands acting in their bidentate form have been prepared and characterized. Similar cationic complexes with the symmetrical bidentate dichalcogenide ligands dppmS₂ and dppmSe₂ have been described. These compounds react with sodium hydride in tetrahydrofuran or with thallium pyrazolate in dichloromethane to yield the new cationic complexes [(η⁵C₅Me₅)Ir{η³(EPPh₂)₂CH-C,E,E′}]⁺ (E = S, Se) in which the anionic methanide dichalcogenide ligand is acting as a tripod ligand with a C,E,E′-donor set. However, the complexes [(η⁵C₅Me₅)IrCl(η²dppmE₂)]BF₄ react with P(OMe)₃ in the presence of TIBF₄, to give the dicationic compounds [(η⁵C₅Me₅)Ir{P(OMe)₃}(η²dppmE₂)](BF₄)₂. In these complexes, the P(OMe)₃ ligand is transformed into a coordinated PO(OMe)₂ group by reaction with sodium iodide in acetone. The structure of the complex [(η⁵C₅Me₅)Ir{PO(OMe)₂}(η²dppmS₂-S,S′)]BF₄ · 0.5Me₂CO have been determined by single crystal X-ray diffraction methods.