[(1,2,5,6-η)-Cycloocta-1,5-diene](1-ethyl-4-isobutyl-1,2,4-triazol-5-ylidene)(triphenylphosphane)iridium(I) tetrafluoridoborate dichloromethane hemisolvate

Abstract

A new triazole-based N-heterocyclic carbene IrI cationic complex with a tetrafluoridoborate counter-anion and hemi-solvating dichloromethane, [Ir(C8H12)(C8H15N3)(C18H15P)]BF4·0.5CH2Cl2, has been synthesized and structurally characterized. There are two independent ion pairs in the asymmetric unit and one dichloromethane solvent molecule per two ion pairs. The cationic complex exhibits a distorted square-planar conformation around the IrI atom, formed by a bidentate cycloocta-1,5,diene (COD) ligand, a triphenylphosphane ligand, and an N-heterocyclic carbene (NHC). There are several close non-standard H...F hydrogen-bonding interactions that orient the tetrafluoridoborate anions with respect to the IrI complex molecules. The complex shows promising catalytic activity in transfer hydrogenation reactions. The structure was refined as a non-merohedral twin, and one of the COD molecules is statistically disordered.

Keywords

• iridium
• n-heterocyclic carbene
• non-merohedral twin
• crystal structure