Novel trialkylstibane iridium(I) and iridium(III) complexes including the X-ray crystal structure of five-coordinate [IrCl(C2H4)(2)(SbiPr(3))(2)]

The reaction of [IrCl(C8H14)(2)](2) (2) With SbiPr(3) in the presence of H-2 yields the dihydridoiridium(III) complex cis,mer-[IrH2Cl(SbiPr(3))(3)] (3) which on treatment with CO and with HC=CR (R=Ph, CO(2)Me) affords the octahedral derivatives [IrH2Cl(CO) (SbiPr(3))(2)] (4) and [IrHCl(C=CR) (SbiPr(3))(3)] (5, 6), respectively. The stibane ligand trans to hydride in 5 and 6 is rather labile and, therefore, 5 and 6 react with pyridine to give [IrHCl(C=CR)(py)(SbiPr(3))(2)] (7, 8). Five-coordinate bis-(stibane)iridium(I) complexes [IrCl(C2H4)(2)(SbR(3))(2)] (10-12)were prepared from [IrCl(C2H2)(2)](2) (9) and four equiv, of SbR(3) (R=iPr, Me, Ph). The X-ray crystal structural analysis of 10 reveals a distorted trigonal-bipyramidal geometry around the metal center with one stibane ligand and the two olefinic Ligands in the equatorial plane. Compound 10 reacts with NaC5H5 to yield [C5H5Ir(C2H4)(SbiPr(3))] (13) and with different alkynes by partial or complete displacement of the ethene ligands to give trans-[IrCl(PhC=CPh)(SbiPr(3))(2)] (14), [IrHCl(C=CTol) (C2H4)(SbiPr(3))(2)] (15), and trans-[IrCl{=C=C(SiMe(3))R}(SbiPr(3))(2)] (16, 17), respectively.