202335-45-3Relevant academic research and scientific papers
Reactivity and chemical exchange processes of bis(ether-phosphine) iridium(III) complexes
Lindner, Ekkehard,Gierling, Karlheinz,Fawzi, Riad,Steimann, Manfred
, p. 13 - 22 (1998)
The orthometalated iridium(III) complex ClIrH(P OCH2) (P O) (P OCH2=η2 (P,OCH2) coordination of Cy2PCH2CH2OCH2, P O =η2(P,O) coordination of Cy2PCH2CH2OCH3) (1) reacts with CS2, HCl, and H2 under re-formation of the methoxy group to give ClIr(η2-CS2)(P～O)2 (3) (P～O=η1(P) coordination of Cy2PCH2CH2OCH3), trans-( P O )(P～O)Ir(H)Cl2 (4a) and ClIrH2( P O )(P～O) (5), respectively. Upon the reaction of 1 with CO the orthometalation is maintained to yield the carbonyl adduct ClIrH(CO)(P OCH2)(P～O) (2). Compounds 4a and 5 represent potentially unsaturated species weakly protected by the ether moiety which acts as an intramolecular solvent. The chelated five-membered ring in 4a, cis-( P O ) (P～O)Ir(H)Cl2 (4b) and 5 can easily be cleaved by carbon monoxide, pyridine and CS2 whereby the complexes Cl2IrH(CO)(P～O)2 (7), ClIrH2(C5H5N)(P～O)2 (10), ClIrH2(CO) (P～O)2 (11) and the dithioformato complex cis-(P～O)2Ir(H)Cl(S2CH) (13a) are formed. In toluene 13a isomerizes to give the trans-product 13b. Comparative NMR studies on the fluxional behavior of the ether phosphine ligands of the five monochelated complexes 4a,b, 5, IrH3(P～O)2(6) and Cl3Ir( P O ) (P～O) (9a) were performed to determine the dependence of the exchange rates on the strength of the iridium-(ether) oxygen bond. Complex 9b, the phenyl congener of 9a, crystallizes in the orthorhombic space group Pna21 with Z=4. The cell dimensions arc a= 1695.2(3), b= 1093.4(2), c= 1621.5(9) pm, R1=0.018 and wR2=0.042.
