Efficient near-infrared luminescence from bis-cyclometalated iridium(iii) complexes with rigid quinoline-derived ancillary ligands.

Five new near-infrared (NIR) phosphorescent bis-cyclometalated iridium(iii) complexes, partnering highly conjugated cyclometalating ligands with quinoline-derived ancillary ligands, have been developed. These complexes have peak NIR luminescence wavelengths from 711 to 729 nm, with photoluminescence quantum yields ranging from 0.042 to 0.36.