Synthesis and photophysical properties of a non-symmetrically substituted phthalocyanine-pyrene conjugate

Abstract

An unsymmetrical zinc phthalocyanine (ZnPc) (5) bearing one pyrene (Py) and six tertbutylphenoxy units was synthesized in 3 steps. The unsymmetrical zinc phthalocyanine carrying theprotecting group was synthesized in the first step. In the second stage, the protecting group was removedand in the final stage pyrene structure was introduced with the Sonagashira coupling reaction. The newcompound was characterized by using spectroscopic techniques. The photophysical measurements of theconjugated structure were performed to determine the effect of the pyrene group on the fluorescence ofPc. It was determined that the absorption of the pyrene structure around 350 nm was overlapping with theB-band of phthalocyanine after conjugation. Fluorescence quantum yield (ΦF) and lifetime (τF) werecalculated. The fluorescence quenching examinations were performed by adding the different concentrationof 1,4-benzoquinone (BQ) in N,N-dimethylformamide (DMF) and the Stern-Volmer constant (Ksv) andquenching constant (kq) values of unsymmetrical zinc phthalocyanine (5) were determined.