Electrochemical and Adsorption Properties of Novel Phthalocyanines with Four 16-Membered Diazadithia Macrocycles

Abstract

<jats:p> Cyclic voltammetric measurements of Cu (II) and Ni (II) phthalocyanines with four 16-membered diazadithia macrocycles (1 and 2) and pentanuclear Ni (II) phthalocyanine bearing four Cu (II) ions in diazadithia macrocycles at the peripheral positions (3) have been carried out on platinum in DMSO and in aqueous medium 3 showed strong adsorption properties in DMSO and especially in aqueous medium, possibly as a result of the interaction between the copper ions in the four macrocycles and the platinum working electrode. Interestingly, the oxidation peak of 3 was split into two waves in aqueous medium. This behaviour is discussed in terms of disaggregation of the mixed valence species produced by the oxidation of aggregated species. A mechanism for both the oxidation of the complex and the splitting of the oxidation peak into two waves is suggested. </jats:p>

Electrochemical, Spectroelectrochemical, and Electrocatalytic Dioxygen Reducing Properties of Peripheral Tetra‐2,6‐dimethoxyphenoxy Substituted Phthalocyanines

“…In addition, it is known that Pc ring-based electron transfers occur relatively at higher potentials. Thus, it is most probable that the first reduction and the first oxidation processes of 3 occur on the central metal and then, the remaining processes are Pc ring-based [23]. In that case, ΔE 1/2 value of this compound, i. e., the half-peak potential difference between the first oxidation and the first reduction processes, does not match the HOMO-LUMO gap.…”

“…The electrocatalytically active patterns for these measurements were setup in a medium similar to the working conditions of a proton exchange membrane fuel cell and direct methanol fuel cell for ensuring applicability in this system. 3),9 (10), 16 (17), 23 (24)-tetrakis- (2, 6-dimethoxyphenoxy)phthalocyanine (2) 0.10 g (0.36 mmol) 4-(2,6-dimethoxyphenoxy)phthalonitrile (1) and 15 mL of dry n-pentanol were stirred under reflux in a nitrogen atmosphere at 140 °C for 15 min. To the reaction mixture 25 mg granular lithium was added and the reaction mixture was stirred for a further 2 hours at 140 °C.…”

Synthesis, electrochemistry, and in situ spectroelectrochemistry of a new water-soluble zinc phthalocyanine substituted with naphthoxy-4-sulfonic acid sodium salt

“…In our previously studies, we have reported the synthesis, electrochemical, and spectroelectrochemical properties of mono metal phthalocyanines [23][24][25], dimeric phthalocyanine [26] , double-decker phthalocyanines [27][28][29], and some vic-dioxime metal complexes [30][31][32][33][34] in aqueous and nonaqueous media. We report herein the synthesis and characterization of a new highly water-soluble zinc phthalocyanine NhtZnPc bearing naphthoxy-4-sulfonic acid sodium salt.…”