[CP-ASTERISK-IR(P(O)(OME)2)3]-, AN IRIDIUM(III) PHOSPHONATE COMPLEX ACTING AS A CHELATING OXYGEN LIGAND - SYNTHESIS AND COORDINATION CHEMISTRY

The anionic iridium complex [(C5Me5)Ir{P(O)(OMe)2}3]- (L-) has been pr epared as sodium salt from the corresponding trimethyl phosphite compl ex [(C5Me5)Ir{P(OMe)3}3](ClO4)2. L- reacts with metal ions M2+ to give ML2. With [PtMe3]2SO4 - 4H2O in water and with [{RhCl(cod)}2], cod = 1,5-cyclooctadiene, in cyclohexane solution the air-stable heterobimet allic complexes [LPtMe3] and [LRh(cod)] are formed. The rhodium comple x [(C5Me5)Rh{P(O)(OMe)2}3]- (L'-) similarly gives [L'PtMe3] and [L'Rh( cod)]. [LRh(cod)] and [L'Rh(cod)] react with CO gas (1 atm.) to yield [LRh(CO)2] and [L'Rh(CO)2]. Partial decarbonylation of these dicarbony l complexes at room temperature leads to the tetranuclear complexes [L 'Rh(mu-CO)3RhL'](Rh-Rh) and [LRh(mu-CO)3RhL](Rh-Rh).