Synthesis and near IR photoluminescence of Os(II) bis(2,2′-bipyridine) (3,8-diarylethynyl-1,10-phenanthroline) complexes: anomalous behavior in the 3,8-dinitrophenylethynyl-substituted homologue

The title compounds are photoluminescent in the near ir: for X = H, λem,max = 815 nm, and for X = OCH3, λem,max = 795 nm. If X = NO2, the MLCT excited state is quenched via intramolecular electron transfer and no photoluminescence is observed.