Synthesis and spectroscopic investigation of boronic esters of metal-free fluorinated and non-fluorinated phthalocyanines

- Boronic acid substituted phthalonitriles and phthalocyanines were prepared.
- Aggregation tendencies of metal-free phthalocyanines were investigated.
- Photophysical properties of these phthalocyanines have been investigated.
- The fluorescence quenching behaviour of these phthalocyanines was also reported.

Phthalonitriles and metal-free phthalocyanines substituted with 2,3-dihydroxypropoxy and [2,3,5,6-tetrafluoro-4-(2,3-dihydroxypropoxy)]benzyloxy groups were synthesized. Their complexes with phenylboronic acid were prepared in THF at reflux in the presence of molecular sieves. The new compounds were characterized by using elemental analyses, FT-IR, UV-vis, 1H NMR, 19F NMR, 11B NMR, and MALDI-TOF MS spectral data. Aggregation tendency of phthalocyanine complexes in relation to their concentrations were investigated by changes in their absorption spectra. Furthermore, photophysical and photochemical properties of metal-free phthalocyanines were investigated in ethanol and dichloromethane. The fluorescence quenching properties of synthesized phthalocyanines were investigated using 1,4-benzoquinone in dichloromethane.

Phthalonitriles and metal-free phthalocyanines substituted with propane-1,2,3-triol and (2′,3′,5′,6′-tetrafluoro-4′-propane-1,2-diol)benzyloxy groups were synthesized. Their complexes with phenylboronic acid were prepared and characterized. Photophysical and photochemical properties of these phthalocyanines were investigated in ethanol and dichloromethane. The fluorescence quenching behaviour of the synthesized phthalocyanines were investigated using 1,4-benzoquinone in dichloromethane.129