Synthetic Metals 161 (2011) 1946–1952 Contents lists available at ScienceDirect Synthetic Metals j o ur nal homep ag e: www.elsevier.com/locate/synmet 3,4-Ethylenedioxythiophene substituted phthalocyanines Hasan Kutay Yıldız a , Sibel Eken Korkut a , Atıf Koca b , M. Kasım S ¸ ener a,∗ a Department of Chemistry, Arts and Sciences Faculty, Yıldız Technical University, 34210, Davutpas ¸ a, ˙ Istanbul, Turkey b Department of Chemical Engineering, Engineering Faculty, Marmara University, 34722, Kadıköy, ˙ Istanbul, Turkey a r t i c l e i n f o Article history: Received 27 April 2011 Received in revised form 21 June 2011 Accepted 30 June 2011 Available online 23 July 2011 Keywords: Phthalocyanine EDOT Electropolymerization PEDOT Electrochemistry Spectroelectrochemistry a b s t r a c t Zinc and cobalt phthalocyanines, peripherally functionalized with electroactive and electropolymeriz- able groups were synthesized and their electrochemical, spectroelectrochemical, and electrocolorimetric properties were studied. While cobalt phthalocyanine gives both metal-based and ring-based redox processes, zinc phthalocyanine shows only ring-based electron transfer processes. Any redox signal belonging to thiophene groups is recorded within the potential window of the electrolyte system. However, when the complexes are over-oxidized with more positive switching potential, electropoly- merization of the complexes on the working electrode are recorded. Presence of the EDOT groups differentiates the colors of the electrogenerated anionic and cationic forms of the complexes which indicate possible electrochromic applications of the complexes. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Poly(3,4-ethylenedioxythiophene) (PEDOT) has received tremendous growth of interest in the last decade and has become one of the most investigated conducting polymers for academic research and also for various industrial applications. Such interest results from its remarkable conducting properties associated with a high chemical stability. On this basis, and in order to obtain polymers combining PEDOT specificities to various additional properties, synthetic efforts have been devoted towards the prepa- ration of substituted EDOT-based monomers (3,4-ethylenedioxy- thiophene). Maintaining the integrity of the PEDOT polycon- jugated backbone implies that substitution of the monomer is carried out on the ethylenedioxy bridge [1–7]. Phthalocyanine (Pc) dyes have been also the subject of study during the last decade because of their high absorbance in the visible region, good electron mobility, and good thermal and photo-stability [8,9]. These macrocycles, alone or in combination with other electro- and photoactive moieties, have been ideal building blocks for the construction of molecular materials with designed electronic and optical properties [10–13]. To the best of our knowledge there is only one publication on EDOT functionalized phthalocyanines in the literature: in 2000 Kingsborough and Swager reported the synthesis and electropolymerization of an unsymmetrically EDOT substituted nickel phthalocyanines [14]. ∗ Corresponding author. Tel.: +90 2123834176; fax: +90 2123834134. E-mail address: mkasimsener@gmail.com (M. Kasım S ¸ ener). In the present work, the synthesis and characterization of new phthalocyanine derivatives carrying an EDOT unit on each benzo group is described. The solution redox properties, spectroelectro- chemical investigation of the metallophthalocyanines (MPcs) are studied using various electrochemical techniques in DMSO on a platinum electrode. Also, the electrochemical polymerizations of these complexes are performed in DMSO/TBAP solvent/electrolyte system. 2. Experimental IR spectra were recorded on a Perkin Elmer Spectrum One FT- IR (ATR sampling accessory) spectrophotometer, and electronic spectra on an Agilent 8453 UV-Vis spectrophotometer. Elemental analyses were performed on a Thermo Flash EA 1112. 1 H and 13 C NMR spectra were recorded on a Bruker Ultra Shield Plus 400 MHz spectrometer using TMS as an internal reference. Mass spectra were measured on a Bruker Microflex LT MALDI-TOF MS and Micro TOF ESI-MS. Melting point was determined on an Electrothermal Gal- lenkamp apparatus. All reagents and solvents were of reagent grade quality and were obtained from commercial suppliers. In particular, special reagents 4-nitrophthalonitrile and hydroxymethyl-EDOT were commercially available and purchased from Aldrich. The homogeneity of the products was tested in each step by TLC (SiO 2 ). The electrochemical and spectroelectrochemical measurements were carried out with a Gamry Reference 600 potentio- stat/galvanostat utilizing a three-electrode cell configuration at 25 ◦ C. For cyclic voltammetry (CV), and square wave voltamme- 0379-6779/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.synthmet.2011.06.040