Effects of peripheral substitutions on the singlet oxygen quantum yields of monophthalocyaninato ytterbium(iii) complexes?

RSC Advances Pub Date: 2015-02-20 DOI: 10.1039/C5RA02569A

Abstract

A new monophthalocyaninato ytterbium(III) complex 5 with eight 3,5-di-t-butylphenoxyl substituents at peripheral positions is synthesized. X-ray structural analysis of 5·CHCl3·MeOH reveals that the Yb3+ ion is seven-coordinate, surrounded by four nitrogen atoms from the phthalocyaninate dianion and three oxygen atoms from the anionic tripodal LOMe? ligand {LOMe? = [(cyclopentadienyl)tris(dimethylphosphito) cobaltate(III)]}. The effects of substituents on the relative singlet oxygen (1O2) quantum yields of monophthalocyaninato ytterbium(III) complexes are investigated through comparison. It is found that the monophthalocyaninato ytterbium(III) complex has higher 1O2 quantum yield than its corresponding phthalocyaninate ligand. The introduction of a 3,5-di-t-butylphenoxy substituent on the microcycle can enhance the yield of singlet oxygen. Due to the heavy-atoms of both iodine and lanthanide ions, the ytterbium(III) complex 4 based on tert-butyl and iodine substituted phthalocyanine ligands has the highest 1O2 quantum yield (0.82).

Graphical abstract: Effects of peripheral substitutions on the singlet oxygen quantum yields of monophthalocyaninato ytterbium(iii) complexes
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