Synthesis and spectroelectrochemistry of new phthalocyanines with ester functionalities

• Published in: Dyes and pigments 2012-03, Vol.92 (3), p.1114-1121
• Main Authors: Sevim, Altuğ Mert, Arıkan, Sibel, Koca, Atıf, Gül, Ahmet
• Format: Article
• Language: English
• Subjects: Agglomeration; Carboxylic acids; Cationic; Color; DCC; Derivatives; Electrochemistry; Electrocolorimetry; Esterification; Esters; Phthalocyanine; Solvents; Spectra; Spectroelectrochemistry
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2011.07.015

Metal-free (H 2Pc) and metallophthalocyanines (MPc; M: Co, Zn) with four n-pentyl ester of thioglycolic acid groups have been synthesized by the esterification of the corresponding carboxylic acid derivatives with n-pentanol. The novel phthalocyanine compounds were characterized by elemental analyses, mass, FT-IR and UV–Vis spectral data. The aggregation investigations carried out in different concentrations and solvents indicate that ester substituted metal-free and metallo-phthalocyanine compounds have not shown any aggregation behavior in the concentration range of about 10 −5 M. Electrochemical and in-situ spectroelectrochemical measurements give common MPc based redox behaviors which supported the proposed structure of the complexes. While CoPc gives both metal-based and ring-based redox processes, H 2Pc and ZnPc give only ring-based electron transfer processes. In-situ electrocolorimetric method was applied to investigate the color of the electro-generated anionic and cationic forms of the complexes. ► Phthalocyanines with thioglycolic acid pentyl ester substituents were synthesized. ► Their aggregation vs. concentration-solvent polarity has been investigated. ► Only CoPc gives metal-based e − transfer processes in addition to ring-based ones. ► Electrocolorimetric method showed the color of the electro-generated ionic forms.