Tetra and octa(2,6-di-iso-propylphenoxy)-substituted phthalocyanines: a comparative study among their photophysicochemical properties

Abstract

This work reports on the synthesis of novel metal free, zinc, aluminum, gallium and indium tetra and octa (2,6-di-iso-propylphenoxy)-substituted phthalocyanine derivatives. UV-visible and 1H NMR analyses confirm that a non-planar conformation, adapted by the phenoxy substituents due to steric interaction in both derivative series, perfectly discourage cofacial aggregation. Fluorescence quantum yields vary as a function of the number of substituents on the ring periphery, while the fluorescence lifetimes display no distinct trend. Triplet quantum yields are significantly larger for the tetra 2,6-di-iso-propylphenoxy- substituted derivatives relative to their corresponding octa-substituted species. However there was no overall trend in the triplet lifetime values. For almost all of the phthalocyanine derivatives, singlet oxygen was produced with relatively good quantum yields. This study explores the possibility of fine-tuning their physicochemical properties by simple structural modification.

Synthesis, spectroscopy, and photophysical properties of newly magnesium (II) phthalocyanine

“…The ΦF value of the MgPc 2 was lower than unsubstituted magnesium (II) phthalocyanine in DMF [27], which implies that the presence of the 2,6-dimethoxyphenoxy units reduced the fluorescence quenching of the Pc molecule. The ΦF value of the MgPc 2 is similar and typical of the other studied magnesium (II) Pc in DMF [37][38][39][40][41][42][43][44][45][46][47]. Fluorescence lifetime (τF) refers to the average time a molecule stays in its excited state before fluorescing, and its value is directly related to that of ΦF, i.e.…”

“…In DMF, the τF value of the substituted MgPc 2 is 4.65 ns and longer compared to unsubstituted magnesium (II) phthalocyanine [27], suggesting less quenching by substitution. The τF value of the MgPc 2 is typical for the metallo-phthalocyanines [37][38][39][40][41][42][43][44][45][46][47]. The natural radiative lifetime (τ0) and the rate constants for fluorescence (kF) value of the MgPc 2 are 5.81× 10 −7 s -1 and 17.22 ns, respectively.…”

Synthesis, characterization and investigation of the photophysical and photochemical properties of highly soluble novel metal-free, zinc(ii), and indium(iii) phthalocyanines substituted with 2,3,6-trimethylphenoxy moieties

“…The fluorescence lifetimes of the Pcs in DMF were observed within the range expected for Pcs (Table 2). [33][34][35] 2). On the other hand, the Φ Δ values of the substituted In(OAc)Pcs (3 and 4) and ZnPcs (5 and 6) were higher than those of their unsubstituted counterparts (In(OAc)Pc and ZnPc).…”

High Photosensitized Singlet Oxygen Generating Zinc and Chloroindium Phthalocyanines Bearing (4‐isopropylbenzyl)oxy Groups as Potential Agents for Photophysicochemical Applications

“…97 which are higher than the literature of Zn (II) and In(III) phthalocyanines . In particular, higher singlet oxygen quantum yields were also obtained with respect to similar phthalocyanine complexes in the literature …”