Deep colour tuneability of heteroleptic Ir(III) complexes through second sphere coordination

Novel iridium (III) complexes with different systems of cyclo-metallating ligands bearing the general formula [Ir(C^N)2(N^N)] were synthesized, characterized and their photophysical properties measured. Incorporation of guanidine moieties into iridium complexes allows us to introduce a hydrogen-bonding array for the formation of self-assembled iridium hydrogenbonded systems. Through a series of UV-vis binding studies we demonstrated the host-guest chemistry of these systems display high levels of colour tuneability. The introduction of these hydrogen-bond modifications was also shown to have significant impacts on chromaticity, quantum yields and lifetimes with emphasis on energy transfer studies based on secondsphere coordination methodology.