An eta(1)-aldehyde complex and the role of hydrogen bonding in its conversion to an eta(1)-imine complex

2-Pyridinecarboxaldehyde displaces Me(2)CO from [IrHz(Me(2)CO)(2)(PPh(3))(2)](+) to give a chelating N,O-bound product containing an eta(1)-O-bound aldehyde group. This is converted to the eta(1)-N-bound imine complex with a variety of substituted amines. When the amine contains a suitably positioned -OH group, intramolecular O-H ... H-Ir dihydrogen bonds are detected in the products. This hydrogen bonding influences the relative rates of product formation from 2- and 4-aminophenol (rate ratio 6:1), where only the 2-isomer is capable of forming an intramolecular H-bond.