The heterospin cobalt complexes: peculiarities of high-resolution NMR spectra

Autor: V.K. Voronov, I.A. Ushakov, E.A. Funtikova
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Heliyon, Vol 8, Iss 4, Pp e09202- (2022)
Druh dokumentu: article
ISSN: 2405-8440
DOI: 10.1016/j.heliyon.2022.e09202
Popis: The high-resolution 1H and 13C NMR spectra (CHCl3 solution) of sterically non-rigid heterospin complexes CoL2, CoL2-dipy, and CoL2-phen (where L is 4-(3′,3′,3′-trifluoro-2′-oxopropylidene)-2,2,5,5-tetramethyl-3-imidazolidine-1-oxyl) have been studied. The specific of the NMR phenomenon in paramagnetic systems is briefly analyzed. It is shown that the NMR spectra modified by hyperfine coupling can be successfully employed for investigation of the complexation processes. In accordance with the common protocols, the 1H and 13C NMR signals are assigned using the information on 13С – 1Н spin-spin coupling. In addition, the preliminarily recorded 1H and 13C NMR spectra of radical L are also used in the work.The temperature dependences of 1H and 13C paramagnetic shifts in the complexes under study have been obtained. A fundamental feature of these dependences is that they obey to the Curie law in a fairly wide temperature range (up to 100 °C). This observation can be used to control intramolecular processes of sterically nonrigid heterosystems in solutions.
Databáze: Directory of Open Access Journals