Synthesis and optical properties of antimony(v) complexes of a trianionic N2O2-type tetradentate dipyrrin ligand

LSbCl2, an air- and moisture-stable antimony(v)–dipyrrin complex at room temperature, was obtained by treating an excess amount (20 eq.) of SbCl3 with a trianionic N2O2-type tetradentate dipyrrin ligand (L) under visible-light irradiation and O2 atmosphere. The Cl ligands in LSbCl2 were replaced by OH ligands via hydrolysis, yielding LSb(OH)2. Further, the molecular structures and optical properties of the Sb(v)–dippyrin complexes were investigated. While LSbCl2 was non-fluorescent, LSb(OH)2 exhibited an intense red fluorescence with a photoluminescence quantum yield of 68%.