Synthesis, acid-base interactions, and photostability of copper(ii) tetrakis(3,5-di-tert-butylbenzoyloxy)phthalocyanine

• Published in: Russian chemical bulletin 2021-12, Vol.70 (12), p.2405-2415
• Main Authors: Malyasova, A. S., Kostrova, E. A., Abramov, I. G., Maizlish, V. E., Koifman, O. I.
• Format: Article
• Language: English
• Subjects: Benzene; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Copper; Dichloromethane; Electron density; Full Articles; Inorganic Chemistry; Molecular structure; Nitrogen atoms; NMR; Nuclear magnetic resonance; Organic Chemistry; Protonation
• ISSN: 1066-5285; 1573-9171
• DOI: 10.1007/s11172-021-3360-7

3,4-Dicyanophenyl 3,5-di- tert -butylbenzoate was synthesized for the first time. Copper tetrakis(3,5-di- tert -butylbenzoyloxy)phthalocyaninate was obtained also for the first time from this compound using template cyclotetramerization. Prepared compounds were identified by UV-vis, IR, 1 H and 13 C NMR spectroscopies. The features of the acid-base interaction and the acidity constants of the copper tetrakis(3,5-di- tert -butylbenzoyloxy)phthalocyaninate protonated forms, as well as copper tetra(4- tert -butyl)phthalocyaninate and its ligand in the system CH 2 Cl 2 —100% trifluoroacetic acid were studied. It was found that the macrocycles protonation includes two reversible stepwise reactions, namely, mono- and diprotonation at the meso nitrogen atoms. The acidity constants dependence on the chemical structure of molecules has been revealed. The phthalocyanines photocatalytic stability in benzene was also investigated. It was shown that an increase in the electron-donating properties of the macrocycle decreases the complex stability, and vise versa , a decrease of the electron density in the macrocycle increases the photostability.