The electronic properties of the eight new silylated complexes and the parent complex IrPic were investigated using density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations. All complexes showed extremely similar electron density distributions (see Table ), with the addition of the trimethylsilyl group having little impact on the calculated electronic properties of most of the complexes. The HOMO of all the complexes is distributed across the iridium center and the phenylpyridine ligands, while the LUMO is located on the ancillary picolinate ligand. Complexes that contain trimethylsilyl groups at C4, (C4, C4N4 and C4N5), possess LUMOs that are distributed across both the phenylpyridine and picolinate ligands. The LUMO energy levels remain essentially the same across the series of complexes, while there is a moderate destabilisation of up to 90 mV of the HOMO compared to Irpic.