Hydrogen elimination in the thermal decomposition of iridium-n-alkyl complexes

Article abstract of DOI:10.1016/0022-328X(94)87149-3

Iridium complexes L2Ir(CO)X (L = PPh3, P(p-FC6H5)3, CO; X = Cl, I) and L2Ir(CO)X3 (L = PPh3, P(p-FC6H5)3; X = Cl, I) were allowed to react with CH3(CH2)6CD2Li and CH3(CH2)5CD2CH2Li to form the respective n-octyliridium complexes.Thermal decomposition of these complexes yielded solely D2C=CH(CH2)5CH3 and CHD2(CH2)6CH3 from the 1,1-dideuteriooctyliridium complexes and H2C=CD(CH2)5CH3 and CDH2CD2(CH2)5CH3 from the 2,2-dideuteriooctyliridium complexes.Thus, productive decomposition of the n-alkyliridium complexes occurred exclusively by a β-hydrogen elimination mechanism.This is in accord with the previously reported reaction of (PPh3)2Ir(CO)Cl with CH3(CH2)5CD2CH2Li <1> and demonstrates that changing the steric and electronic nature of the donor ligands on the iridium is insufficient to induce productive decomposition by α-hydrogen elimination.Keywords: Iridium; Alkyls; Elimination reactions