Synthesis and optical properties of antimony(V) complexes of a trianionic N 2 O 2 -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 SbCl 3 with a trianionic N 2 O 2 -type tetradentate dipyrrin ligand (L) under visible-light irradiation and O 2 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%.