Synthesis,characterisation and electrochemical investigation of phthalocyanines with pendant 4‐{2‐[2‐(4‐tert‐butylphenoxy)ethoxy]ethoxy} substituents

In this study, a novel metal‐free phthalocyanine and three metallophthalocyanines carrying four 2‐2‐(4‐tert‐butylphenoxy)ethoxy groups on the periphery were prepared by cyclotetramerisation of a dinitrile derivative in the presence of the corresponding divalent metal salts zinc(ii ), cobalt(ii ), copper(ii )]. These new phthalocyanine compounds have been characterised by infrared, ¹H and ¹³C nuclear magnetic resonance and electrospray mass spectroscopies and elemental analysis. The electrochemical properties of the metal‐free, zinc(ii ) and cobalt(ii ) phthalocyanines were investigated by cyclic voltammetry and differential pulse voltammetry methods. The cobalt complex showed a metal‐based reduction process, while the metal‐free and zinc(ii ) phthalocyanines showed ligand‐based electron transfer processes. It has been found that the absorption spectra substantially depend on concentration. It has been shown that these changes are attributable to the association of the phthalocyanine molecule. The number of molecules in the associates and the equilibrium constants for this association are determined.