| Autor: |
Belova, Svetlana A., Dudkin, Semyon V., Belov, Alexander S., Danshina, Anastasia A., Dorovatovskii, Pavel V., Budnikova, Yulia H., Khrizanforova, Vera V., Bratskaya, Svetlana Yu., Balatskiy, Denis V., Voloshin, Yan Z. |
| Předmět: |
|
| Zdroj: |
New Journal of Chemistry; 11/7/2024, Vol. 48 Issue 41, p17831-17848, 18p |
| Abstrakt: |
Title hybrid iron(II)- and cobalt(III)-centered complexes were prepared in moderate yields using the template reactions of 3-acetylpyrazoloxime as a chelating ligand synthon with a Lewis-acidic zirconium or hafnium(IV) phthalocyaninate on the corresponding 3d-metal ion as a matrix. Formation of the cobalt(III)-centered complexes is observed due to the oxidation of Co2+ cations of the initial cobalt(II) salt. Thus obtained binuclear chloride H-bonded iron(II) and cobalt(III) compounds were characterized using elemental analysis, 1H and 13C {1H} NMR, MALDI-TOF mass, 57Fe Mössbauer (for iron compounds) and UV-vis spectra, and by single-crystal X-ray diffraction (XRD). Their redox properties were studied by cyclic (CV) and differential pulse voltammetry methods, and using spectroelectrochemical experiments. Their encapsulated 3d-metal ions with the electronic d6 configuration are located almost in the center of MN6-coordination polyhedra, the geometry of which is more closer to a trigonal antiprism (TAP, the distortion angle ϕ = 60°) than to a trigonal prism (TP, ϕ = 0°) with ϕ ∼ 40°. FeII–N distances fall in the range 1.913(6)–1.965(7) Å, while the CoIII–N bond lengths are from 1.890(8) to 1.935(8) Å. The geometry of MIVO3N4-coordination polyhedra of their capping metal(IV) ions is intermediate between a capped TAP and a capped TP. In the molecules of ZrIVMIIIMIIMIIZrIV-pentanuclear intracomplexes, (HS)FeIII–N and (LS)CoIII–N distances in their two semiclathrochelate fragments fall in the ranges 1.915(10)–1.980(12) Å and 1.886(13)–1.930(13) Å, respectively, and the geometry of MN6-coordination polyhedra is closer to a TAP (values of ϕ are higher than 30°). The geometry of MN6-polyhedra of the HS cross-linking metal(II) ions between them is close to a TAP (values of ϕ are higher than 50°). All the obtained binuclear hybrid complexes exhibit very similar electrochemical patterns. Their CVs contain quasi-reversible or irreversible three reduction and three oxidation waves. The potentials of electrochemical reductions, assigned to the Pc-localized redox processes, are close to each other. The first of them is a quasi-reversible process attributed to the Pc-based one-electron reduction, while the first oxidation wave was assigned to the metal-centered M2+/3+ redox couples. The spectroelectrochemical data confirmed an assignment of the aforementioned electrochemical processes. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
