Monoporphyrinate ytterbium(iii) complexes with new ancillary ligands: synthesis, structural analysis and photophysical investigation

Abstract

A method for the preparation of neutral monoporphyrinate ytterbium(III) complexes [Yb(TPP)(L)(H₂O)] from their precursor [Yb(TPP)(H₂O)₃]Cl is presented, where TPP is 5,10,15,20-tetraphenylporphyrinate dianion and L are the bidentate anions of 8-hydroxylquinoline (HOQ), 1-hydroxyl-7-azabenzotriazole (HBTA), 2-benzimidazolylguanidine (HGBI) and 1,1,1,5,5,5-hexafluoro-2, 4-pentanedione (HHFA). The new complexes were characterized by elemental analysis and mass spectroscopy. The structure of [Yb(TPP)(OQ)(H₂O)] was ascertained by single-crystal X-ray diffraction revealing the central ytterbium(III) ion to be seven coordinate. The near-infrared emission efficiency and lifetimes from Yb(III) of these complexes were enhanced due to the substitution of two aqua molecules by bidentate anions.