Electrochemical properties and radical anions of carbocycle-fluorinated quinoxalines and their substituted derivatives

Electrochemical properties and radical anions of carbocycle-fluorinated quinoxalines and their substituted derivatives Full article

Journal

Journal of Physical Organic Chemistry
ISSN: 0894-3230

Output data

Year: 2017, Volume: 30, Number: 8, Article number : e3667, Pages count : DOI: 10.1002/poc.3667

Tags

cyclic voltammetry; DFT calculations; EPR spectroscopy; fluorinated quinoxalines; radical anions

Authors

Shundrin Leonid A. ^1,2 , Irtegova Irina G. ¹ , Vasilieva Nadezhda V. ¹ , Avrorov Pavel A. ¹ , Selikhova Natalia Yu. ³ , Makarov Arkady G. ¹ , Makarov Alexander Yu. ¹ , Slizhov Yuri G. ³ , Zibarev Andrey V. ^1,3

Affiliations

1	(Данные Web of science) Russian Acad Sci, Inst Organ Chem, Novosibirsk 630090, Russia
2	(Данные Web of science) Novosibirsk State Univ, Dept Nat Sci, Novosibirsk 630090, Russia
3	(Данные Web of science) Tomsk State Univ, Dept Chem, Tomsk 634050, Russia

Electrochemical reduction (ECR) and oxidation (ECO) of 5,6,7,8-tetrafluoroquinoxaline (1) and its derivatives bearing various substituents R (7-H (2), 7,8-H-2 (3), 6-CF3 (4), 6-Cl (5), 5,7-Cl-2 (6), 5-NH2 (7), 6-OCH3 (8), 6,7-(OCH3)(2) (9), 6,7,8-(OCH3)(3) (10), 5,6,7,8-(OCH3)(4) (11), 6-OCH3,7-N(CH3)(2) (12), 6-N(CH3)(2) (13), 6,7-(N(CH3)(2))(2) (14), 5,6,7-(N(CH3)(2))(3) (15), and 7,8-cyclo-(=CF-CF = CF-CF=) (16)) in the carbocycle have been studied by cyclic voltammetry in MeCN. For 1-4 and 7-15, the first reduction peaks have been found to be 1-electron and reversible, thus corresponding to the formation of their radical anions (RAs), which are long lived at 295 K except those of 4-6 and 15, 16. Irreversible hydrodechlorination has been observed for 5 and 6 at the first step of their ECR confirmed by EPR detection of corresponding RAs of 2 and 5,7-H-2 derivative of 1 (17) at the next steps. Electrochemically generated RAs of 1-3,7-14, and 17 have been characterized in MeCN by EPR spectroscopy together with DFT calculations at the(U) B3LYP/6-31 + G(d) level of theory using PCM to describe the solvent. A noticeable alternation of spin density on the -NCCN-moiety of quinoxaline has been observed for all RAs possessing R-substitution asymmetry. The comparative electron-accepting ability of 1-15 has been analyzed in terms of their experimental reduction peak potentials and the (U) B3LYP/6-31 + G(d)-calculated gas-phase first adiabatic electron affinities (EAs). The differences in electron transfer solvation energies for 1-15 have been evaluated on the basis of ECR peaks' potentials and calculated gas-phase EAs. The ECO of 1-5 and 7-14 has been found to be irreversible.

Shundrin L.A. , Irtegova I.G. , Vasilieva N.V. , Avrorov P.A. , Selikhova N.Y. , Makarov A.G. , Makarov A.Y. , Slizhov Y.G. , Zibarev A.V.
Electrochemical properties and radical anions of carbocycle-fluorinated quinoxalines and their substituted derivatives
Journal of Physical Organic Chemistry. 2017. V.30. N8. e3667 . DOI: 10.1002/poc.3667 WOS Scopus РИНЦ OpenAlex

Published online:	Nov 29, 2016
Published print:	Aug 1, 2017

Web of science:	WOS:000406979900006
Scopus:	2-s2.0-85006284685
Elibrary:	31014324
OpenAlex:	W2558617182

DB	Citing
Web of science	5
Scopus	6
OpenAlex	4