Synthesis and characterization of terminalalkynyl-substituted unsymmetrical zinc phthalocyanine conjugated with well-defined polymers

• Unsymmetrically terminalalkynyl substituted zinc (II) phthalocyanine is synthesized.
• Statistical condensation method is reported with the unprotected phthalonitrile.
• Well defined PS-Br and PtBA-Br are synthesized by ATRP.
• Click reaction of ZnPc with azido-PS and PtBA yielded Pc-end functional polymers.
• Electrochemical properties of ZnPc and ZnPc-PS are investigated.

Synthesis of unsymmetrically terminalalkynyl substituted zinc (II) phthalocyanine (ZnPc) through an efficient statistical condensation reaction with the unprotected phthalonitrile (2) is reported for the first time. Isolated ZnPc bearing one terminalalkynyl group is a good precursor for Cu(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) reaction which is classified under the term “click chemistry”. This was approved by the successful click reaction between ZnPc and azide end-functional well-defined polymers obtained by atom transfer radical polymerization (ATRP), and consecutive azidation of corresponding bromo end-functional polymers. The click-reaction efficiencies for the formation of Pc-end functional poly(tert-butyl acrylate) (PtBA), and polystyrene (PS) have been found to be 75, 93% respectively. Functionalization of ZnPc with PS increased the chemical stability of the complex but decreased the electrochemical reversibility during redox reactions. In-situ electrocolorimetric measurements of the complexes allowed the quantification of color coordinates of the each electrogenerated anionic and cationic redox species.

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