Deposition of [Ir(COD)(IMes)Cl] complex on the HOPG surface by means of evaporation in vacuum

Abstract

The paper investigates the capability of depositing an organometallic complex of iridium on a solid support by evaporation in vacuum with the support kept at room temperature. The complex [Ir(COD)(IMes)Cl], where COD is 1,5-cyclooctadiene and IMes is 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene, was deposited on the surface of Highly Oriented Pyrolytic Graphite (HOPG), which was previously etched by Ar+ bombardment. The obtained samples [Ir(COD)(IMes)Cl]/HOPG were characterized by X-ray photoelectron spectroscopy (XPS). It was shown that during the deposition of the complex, its evaporation into vacuum occurred without the decomposition of the original molecule. When a layer with a thickness of ≥1 nm was formed on the HOPG surface, most of the complex molecules, which did not contact with the graphite surface, retained their original integrity. Molecules localized in the first monolayer were bound to surface carbon atoms, presumably, through chlorine ions. When the [Ir(COD)(IMes)Cl]/HOPG system was heated in vacuum to temperatures ≥200°C, the coordination sphere of the complex was destroyed, resulting in the formation of iridium metal particles on the HOPG surface.