Pentamethylcyclopentadienyliridium(III) complexes containing tertiary phosphorus chalcogenide ligands: Crystal structure of [(eta(5)C(5)Me(5))Ir{PO(OMe)(2)}{eta(2)(SPPh(2))(2)CH2-S,S'}]BF4 center dot 0.5Me(2)CO

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 dppmS, and dppmSe, have been described. These compounds react with sodium hydride in tetrahydrofuran or with thallium pyrazolate in dichloromethane to yield the new cationic complexes [(eta(5)C(5)Me(5))Ir{eta(3)(EPPh(2))(2)CH-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 [(eta(5)C(5)Me(5))IrCl(eta(2)dppmE(2))]BF4 react with P(OMe)(3) in the presence of TIBF4, to give the dicationic compounds [(eta(5)C(5)Me(5))Ir{P(OMe>(3)}(eta(2)dppmE(2))(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 [(eta(5)C(5)Me(5))Ir{PO(OMe)(2)}(eta(2)dppmS(2)-S,S')]BF4 . 0.5Me(2)CO have been determined by single crystal X-ray diffraction methods.