199164-72-2Relevant academic research and scientific papers
Rhodium and iridium complexes with 2-(diphenylphosphanyl)phenylamido ligands
Dahlenburg, Lutz,Herbst, Konrad
, p. 1693 - 1698 (2007/10/03)
Treatment of frans-[MCl(CO)(PPh3)2] (M = Rh, Ir) with the lithium salts of the bidentate hybride ligands 2-Ph2PC6H4N(R)H [′PN(R)H′; R = H, Me] produced the chelate complexes [M(CO)(PPh3)(′PNR′)] [M/NR = Rh/NH (la), Ir/ NH (2a), Rh/NMe (Ib), Ir/NMe (2b)] containing the CO ligand and the NR substituent in mutual frans-arrangement. 2b was shown by single-crystal X-ray diffraction to possess an amido-nitrogen atom in a trigonal-planar environment. Oxidative addition of H2 to 2b reversibly formed cis-[IrH2(CO)(PPh3)(′PNMe′)] (3), in which H2 has added perpendicular to the N-Ir-CO axis. While both la,b and 2a,b proved to be completely unreactive toward CO2 at ambient temperature and pressure, reactions of la and 2a/b with sulfur dioxide reversibly formed pentacoordinate SO2 adducts, [M(SO2)(CO)(PPh3)(′PNR′)] [M/NR = Rh/NH (4a), Ir/NH (5a), Ir/NMe (5b)] with M-S-bonded pyramidal MSO2 units as established by an X-ray structure analysis of 5 a. Complex 5b reacted with dioxygen to form the sulfato compound [Ir(O2SO2)(CO)(PPh3)(′PNMe′)] (6). Combination of 2a with HCl in CHCl3 at -60°C resulted in protonation of both the iridium and the nitrogen atom to give an ionic chelate complex, [IrHCl(CO)(PPh3)(′PNH2′)]Cl (7), containing one of its NH groups hydrogen-bonded to Ir-Cl. Ring opening of the chelate structure with formation of [IrHCl2(CO)(PPh3)-(PPh2C6H 4N(Me)H-o)] (8) was observed in the analogous reaction of 2b with hydrogen chloride. NMR spectroscopy showed 8 to exist in CDCl3 solution as a mixture of three Ir-PPh2C6H4N(Me)H-o rotamers, stabilized by intramolecular -N(Me)H...ClIr hydrogen bonding. WILEY-VCH Verlag GmbR 1997.
