Diphosphinoazine rhodium(III) and iridium(III) octahedral complexes

Rhodium(III) and iridium(III) octahedral complexes of general formula [MCl3{R2PCH2C(But)double bond; length as m-dashNNdouble bond; length as m-dashC(But)CH2PR2}] (M = Rh, Ir; R = Ph, c-C6H11, Pri, But; not all the combinations) were prepared either from the corresponding diphosphinoazines and RhCl3 · 3H2O or by the oxidation of previously reported bridging complexes [{MCl(1,2-η:5,6-η-CHdouble bond; length as m-dashCHCH2CH2CHdouble bond; length as m-dashCHCH2CH2)}2{μ-R2PCH2C(But)double bond; length as m-dashNNdouble bond; length as m-dashC(But)CH2PR2}] with chlorine-containing solvents. Depending on the steric properties of the ligands, complexes with facial or meridional configuration were obtained. Crystal and molecular structures of three facial and two meridional complexes were determined by X-ray diffraction. Hemilability of ligand in the complex fac-[RhCl3{(C6H11)2PCH2C(But)double bond; length as m-dashNNdouble bond; length as m-dashC(But)CH2P(C6H11)2}] consisting in reversible decoordination of the phosphine donor group in the six-membered ring was observed as the first step of isomerization between fac and mer isomers.