SYNTHESIS AND HAMMETT CONSTANT CORRELATION STUDIES OF NEW FUNCTIONALLY-SUBSTITUTED (ETA-5-CYCLOPENTADIENYL)CARBONYL(TRIPHENYLPHOSPHINE)IRIDIUM COMPOUNDS

A series of functionally substituted (eta(5)-cyclopentadienyl)carbonyl( triphenylphosphine)iridium compounds of the type Ir(eta(5)-C(5)H(4)R)(CO)(PPh(3)) (R = C(O)CH3, CH3, C(O)C6H5, CHO, SiMe(3), NMe(2), CO2CH3, CH2C6H5, CN, Cl) have been prepared from reactions of the corresponding substituted cyclopentadienylthallium, -sodium, or -lithium reagents with trans-chlorocarbonylbis(triphenylphosphine )iridium, or by reaction of these intermediates with chlorotricarbonyliridium and subsequent reaction with triphenylphosphine. The carbonyl stretching frequencies and the (31)p NMR chemical shifts of these compounds have been correlated with various Hammett substituent constants. Greatest linearity was achieved with parameters that represent the sum of the inductive and resonance effects of the substituents.