Spectral-luminescence properties of P^V corrolazines with axial alkoxide ligands

New phosphorus(V) complexes of octaphenyl substituted tetrapyrazinocorrolazines (TPyzCA) containing in the axial positions alkoxide ligands [TPyzCAP(OC 2 H 4 X) 2 ] (X = Pr, NMe 2 , OH) were synthesized using the one-pot procedure and effect of acid on their spectral luminescence and photochemical properties was studied. The presence of fused pyrazine rings increases the ability to bind axial ligands compared to benzo-fused corrolazine (TBzCA). Excited state properties are strongly dependent on the solvation effects. The effect of excited state quenching by photoinduced electron transfer is observed only for the dimethylaminoethoxide complex of TPyzCA in polar solvents, like THF or DMSO. Still, it is absent in dichloromethane, toluene, and for TBzCA derivatives. The hydroxyethoxide complex of TPyzCA and dimethylaminoethoxide complex of TBzCA exhibit efficient fluorescence and high singlet oxygen generation ability in DMSO solution.