Synthesis, characterization and near-infrared photoluminescence of monoporphyrinate lanthanide complexes containing an anionic tripodal ligand

Twelve neutral stable complexes of ytterbium(III) and erbium(III) coordinated by anionic hydridotris(pyrazol-1-yl)borate and meso- tetraphenylporphyrinate, and its derivatives with different substituents in the para position of the phenyl groups, were prepared and characterized. Crystal structure analyses revealed that seven nitrogen atoms, four from the porphyrinate dianion and three from the anionic tripodal ligand, are symmetrically coordinated to the lanthanide ions. Photophysical investigations of the complexes showed an enhancement of near-infrared photoluminescence as compared to aqua-coordinated monoporphyrinate lanthanide complexes. The solvent effect and substituent effects on the photoluminescent properties of the complexes were also investigated