Decarboxylation syntheses of transition metal organometallics VI. Preparations of polyfluorophenyliridium(I) compounds

Article abstract of DOI:10.1016/0022-328X(92)83447-P

The complexes trans-Ir(CO)R(PPh3)2 (R=C6F5, p-HC6F4, or m-HC6F4) have been prepared by reaction of trans-Ir(CO)Cl(PPh3)2 with the appropriate thallium(I) polyfluorobenzoate in pyridine.The rate of decarboxylation falls in the sequence R=C6F5 > p-HC6F4 > m-HC6F4.Intermediate trans-Ir(CO)(O2CR)(PPh3)2 complexes were detected by 19F NMR spectroscopy, and trans-Ir(CO)(O2CC6F5)(PPh3)2 was isolated following reaction of trans-Ir(CO)Cl(PPh3)2 with thallium(I) pentafluorobenzoate in boiling benzene.Heating of trans-Ir(CO)(O2CC6F4H-o)(PPh3)2, formed in situ by a similar metathesis in pyridine, gave the complex , which was formed by cyclometallation and oxidative addition and which, from NMR and spectroscopic data, is considered to have trans-Ph3P ligands, hydride trans to carboxyl, and CO trans to an aryl carbon.