Pj. Roman et Jd. Atwood, CARBONYLATION OF TRANS-IR(CO)CL(TPPTS)(2) AND REACTIVITY OF [IR(CO)(2)(TPPTS)(3)]CL (TPPTS = P(M-C6H4SO3NA)(3)) IN DMSO AND WATER, Organometallics, 16(25), 1997, pp. 5536-5540
Reaction of CO with trans-Ir(CO)(Cl)(TPPTS)(2) in DMSO and H2O give [I
r(CO)(3)(TPPTS)(2)]-Cl (H2O and DMSO) and Ir(CO)(2)(Cl)(TPPTS)(2) (DMS
O only). In both solvents the carbonylation is reversed. by passing N-
2 through the solution. In water, further reactions occur slowly, incl
uding water-gas-shift reactions and formation of Ir(CO)(2)(TPPTS)(3)(). This trisphosphine complex was independently prepared to examine it
s reactions. In DMSO, reaction with CO readily forms Ir(CO)(3)(TPPTS)(
2)(+); no reaction with CO is observed in water. Reaction of Ir(CO)(2)
(TPPTS)(3)(+) with H-2 occurs through TPPTS dissociation giving Ir(CO)
(2)- (H)(2)(TPPTS)(2)(+) initially before reaction with free TPPTS giv
es Ir(CO)(H)(2)(TPPTS)(3)(+) as the final product. Hydrogen bonding fr
om water to the sulfonated phosphine ligands provides a reasonable exp
lanation for the differing ligand substitution behavior in DMSO and H2
O.