Interaction of spin-correlated radical pair with a third radical: Combined effect of spin-exchange interaction and spin-selective reaction

Interaction of spin-correlated radical pair with a third radical: Combined effect of spin-exchange interaction and spin-selective reaction Full article

Journal

Journal of Chemical Physics
ISSN: 0021-9606

Output data

Year: 2019, Volume: 151, Number: 22, Article number : 224308, Pages count : 10 DOI: 10.1063/1.5127812

Authors

Bagryansky Victor A. ¹ , Borovkov Vsevolod ^1,2 , Bessmertnykh Alena O. ^1,2 , Tretyakova Irina S. ¹ , Beregovaya Irina ³ , Molin Yuri N. ¹

Affiliations

1	V.V. Voevodsky Institute of Chemical Kinetics and Combustion, 3 Institutskaya Str., Novosibirsk 630090, Russia
2	Novosibirsk State University, 2 Pirogova Str., Novosibirsk 630090, Russia
3	N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, 9 Lavrentiev Avenue, Novosibirsk 630090, Russia

The reaction of electron transfer between two paramagnetic particles may be strongly dependent on the total spin state of the pair. Such dependence can be used to control electron transfer in a molecular medium via the control of the spin degrees of freedom. In this work, the spin-selective electron transfer has been studied in a three-spin system composed of a spin-correlated radical ion pair (RIP) and the nitroxide radical, TEMPONE. The RIPs were created in an n-hexane solution of tetramethylpiperidine (TMP) and para-terphenyl (p-TP) using X-rays. To monitor the spin evolution of the RIPs with a nanosecond time resolution, the method of time-resolved magnetic field effect in the RIP recombination fluorescence was applied. It was found that increasing the TEMPONE concentration increased the rate of both the radiation-induced fluorescence intensity decay and the paramagnetic relaxation of the spin-correlated RIP. For the three-spin system studied, we developed a theoretical model to calculate the singlet state population of the spin-correlated RIP that described both the spin-selective reaction and the spin-exchange interaction during an encounter between RIP partners and a third radical. It was found that the effect of the spin exchange could be neglected if the rate of the spin-selective reaction is high enough. Based on quantum chemical calculations and experiments, we found that there was a spin-selective distant electron transfer from p-TP radical anions to the TEMPONE radical. Another partner of the RIP, the radical cation formed from TMP, was only involved in the spin exchange interaction with TEMPONE radicals.

Bagryansky V.A. , Borovkov V. , Bessmertnykh A.O. , Tretyakova I.S. , Beregovaya I. , Molin Y.N.
Interaction of spin-correlated radical pair with a third radical: Combined effect of spin-exchange interaction and spin-selective reaction
Journal of Chemical Physics. 2019. V.151. N22. 224308 :1-10. DOI: 10.1063/1.5127812 WOS Scopus РИНЦ

Submitted:	Sep 13, 2019
Accepted:	Nov 12, 2019
Published online:	Dec 12, 2019
Published print:	Dec 14, 2019

Web of science	WOS:000505596000014
Scopus	2-s2.0-85076520906
Elibrary	43218323
OpenAlex	W2996413636