Mono and Double-Decker Lutetium Phthalocyanines Bearing Iodine Groups: Electrochemical and Electrochromic Properties

Abstract

In this study, novel mono 1b (LuPc) and double-decker 1c (LuPc 2 ) lutetium(III) phthalocyanine (Pc) complexes carrying iodine groups have been synthesized and their electrochemical, in-situ spectroelectrochemical, and in-situ electrocolorimetric properties were studied and compared in solution. Electrochemically produced species of 1c displayed distinct spectral and color changes. Thus, spectroelectrochemical and electrocolorimetric measurements of cast film of 1c on indium-tin oxide (ITO) glass were also performed in aqueous solution with the aim of evaluating its applicability as an electrochromic material. ITO/LuPc 2 1c cast film illustrated distinct and reversible green to yellow, green to light blue and light blue to purple color changes due to the electrochemically generated anionic and cationic forms. The film showed high optical and coulombic stabilities and especially high optic contrast during the oxidation process. The response time was also found to be satisfactorily fast for the transitions between green and yellow colors. The results showed that 1c has the potential for usage as an efficient material in electrochromic devices.

Synthesis, characterization and electrochemical properties of novel pyridine phthalocyanine derivatives

“…The potential Table 1). The lower DE 1/2 value for 3 is compatible with values in the literature [26,27,34]. It appears that in complex 3, one of the Pc rings has a -2 oxidation state, while the other one has a -1 oxidation state, which gives a radical structure to the LuPc 2 complexes.…”

“…Accordingly, compound 3 appears to be in the reduced form, not in the form of radical, in DMSO, as evidenced from the absence of a band around 500 nm in its original spectrum prior to application of any constant potential (Fig. 5a) [26]. This finding is further supported by the spectral changes observed during the oxidation process at 0.75 V. As shown in Fig.…”

“…Controlled potential electrolysis of the solution of 3 at suitable peak potentials was carried out to provide additional support for the complete identification of the redox processes, determination the spectra and colors of its electrogenerated anionic and cationic forms and thus, identification of its suitability for usage as a color-changing electrochromic material. Figure 4 represents UV-vis spectral changes It is well known in contrast to a non-coordinating solvent such as DCM, double-decker lanthanide Pcs exist in the reduced form in a coordinating solvent medium [26,27]. Accordingly, compound 3 appears to be in the reduced form, not in the form of radical, in DMSO, as evidenced from the absence of a band around 500 nm in its original spectrum prior to application of any constant potential (Fig.…”

“…Furthermore, this delocalization, including the basic electrochemistry, can be modified by a careful selection of the redox activity of the central metal ions, and by changing the number, position and types of substituents on the Pc ring [23][24][25]. Among Pc derivatives, the syntheses of lanthanide(III) Pcs, especially double-decker lanthanide Pcs, have attracted a great deal of interest due to their unique electrochemical, and electrochromic behavior and the p-p interaction of the Pc rings in the double-decker complexes [26][27][28][29].…”

Toluene vapor sensing characteristics of novel copper(II), indium(III), mono-lutetium(III) and tin(IV) phthalocyanines substituted with 2,6-dimethoxyphenoxy bioactive moieties

“…If the phthalonitrile compound reacts with lutetium(III) acetate in DMF, mono LuPc complex can occur; bis lutetium Pc can be synthesized using pentanol or hexanol with 1,8-diazabicyclo[5.4.0]undec-7-ene (in stronger basic media). In this study, lutetium(III) acetate in DMF was used to synthesize mono LuPc complexes [28].…”