Cobaltacarborane functionalized phthalocyanines: Synthesis, photophysical, electrochemical and spectroelectrochemical properties

•Phthalocyanines carrying cobaltacarborane on the peripheral position were prepared.•Photophysical properties of zinc phthalocyanine were investigated.•Electrochemical and in-situ spectroelectrochemical measurements were carried out.•Cobaltacarborane units extend the redox richness of the metallo-phthalocyanines.

New tetra-cobaltacarborane modified zinc, cobalt and manganese phthalocyanine complexes have been synthesized via nucleophilic attack of the reference hydroxylated phthalocyanines to the oxonium adduct of cobalt bis(dicarbollide). The compounds were characterized by elemental analysis, FT-IR, 1H NMR, 11B NMR, UV–vis and mass spectroscopic data. Photophysical properties of zinc phthalocyanine 6 suggest that it may have potential application as dual sensitizers in the PDT and BNCT treatment of tumors. The electrochemical, in situ spectroelectrochemical and electrocolorimetric properties of these phthalocyanine conjugates were investigated together with reference phthalocyanines. In the case of electroactive Co- and Mn-phthalocyanine with cobaltacarborane substituents, in addition to ring based reduction, metal based reductions in both phthalocyanine core and cobaltocarborane units have been clearly identified.

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