Abstract
Rhodium(III) and iridium(III) octahedral complexes of general formula [MCl3{R2PCH2C(But)=NN=C(But)CH2PR2}] (M = Rh, Ir; R = Ph, c-C6H11, Pri, But) were prepared either from the corresponding diphosphinoazines and RhCl3 • 3H2O or by oxidation of previously reported bridging complexes [{MCl(1,2-h:5,6-h-CH=CHCH2CH2CH=CHCH2CH2 )}2{m-R2PCH2C(But)=NN= C(But) CH2R2}] with chlorine-containing solvents. Depending on steric properties of the ligands, complexes with facial or meridional configuration were obtained.
Crystal and molecular structures of four complexes were determined by X-ray diffraction. Hemilability of ligand in the complex fac-[RhCl3{(C6H11)2PCH2C(But)=NN=C(But)CH2P(C6H11)2}] consisting in reversible decoordination of the phosphine donor group in the six-membered ring was observed.
Variable temperature 31P NMR measurement and subsequent simulation gave a value of concentration of the partially decoordinated species about 1 mol % and a rate of exchange approximately 100 s-1.