Characterisation of fac-tris [2-phenylpyridinato-C2, N]iridium(III) by inelastic neutron scattering spectroscopy and periodic density functional theory

Abstract

Abstract fac-Tris[2-phenylpyridinato-C 2, N]iridium(III) (tris-(2-phenylpyridine) iridium, [Ir(ppy)3]), is a metal complex with applications that range from its use in organic light emitting diodes, to its acting as an efficient photocatalyst for a variety of organic reactions. In this paper the INS spectrum of this material is recorded for the first time and it is analysed by periodic density functional theory calculations of both its trigonal and tetragonal polymorphs. The differences between the calculated INS spectra of the trigonal and tetragonal forms and the isolated molecule demonstrate that the intermolecular interactions play a significant role. This is surprising for what is, nominally, a van der Waals solid.