Pulse EPR of Triarylmethyl Probes: A New Approach for the Investigation of Molecular Motions in Soft Matter

Pulse EPR of Triarylmethyl Probes: A New Approach for the Investigation of Molecular Motions in Soft Matter Full article

Journal

Journal of Physical Chemistry B
ISSN: 1520-6106

Output data

Year: 2018, Volume: 122, Number: 36, Pages: 8624-8630 Pages count : 7 DOI: 10.1021/acs.jpcb.8b07714

Authors

Kuzhelev Andrey A. ^1,2,3 , Krumkacheva Olesya A. ^2,3 , Ivanov Mikhail Yu ^2,3 , Prikhod'ko Sergey A. ⁴ , Adonin Nicolay Yu ⁴ , Tormyshev Victor M. ^1,3 , Bowman Michael K. ^1,5 , Fedin Matvey, V ^2,3 , Bagryanskaya Elena G. ^1,3

Affiliations

1	(Данные Web of science) SB RAS, NN Vorozhtsov Inst Organ Chem, Novosibirsk 630090, Russia
2	(Данные Web of science) SB RAS, Int Tomog Ctr, Novosibirsk 630090, Russia
3	(Данные Web of science) Novosibirsk State Univ, Novosibirsk 630090, Russia
4	(Данные Web of science) SB RAS, Boreskov Inst Catalysis, Novosibirsk 630090, Russia
5	(Данные Web of science) Univ Alabama, Tuscaloosa, AL 35487 USA

Triarylmethyl (TAM) radicals have become widely used free radicals in the past few years. Their electron spins have long relaxation times and narrow electron paramagnetic resonance (EPR) lines, which make them an important class of probes and tags in biological applications and materials science. In this work, we propose a new approach to characterize librations by means of TAM radicals. The temperature dependence of motional parameter <alpha(2)>tau(c), where <alpha(2)> is the mean-squared amplitude of librations and tau(c) is their characteristic time, is obtained by comparison of the 1/T-m phase-relaxation rates at X- and Q-band EPR frequencies. We study three soft matrixes, viz., glassy trehalose and two ionic liquids, using TAMs with optimized relaxation properties OX063D and a dodeca-n-butyl homologue of Finland trityl (DBT). The motional parameters <alpha(2)>tau(c) obtained using TAMs are in excellent agreement with those obtained by means of nitroxide radicals. At the same time, the new TAM-based approach has (1) greater sensitivity due to the narrower EPR spectrum and (2) greater measuring accuracy and broader temperature range due to longer relaxation times. The developed approach may be fruitfully implemented to probe low-temperature molecular motions of TAM-labeled biopolymers, membrane systems, polymers, molecules in glassy media, and ionic liquids.

Kuzhelev A.A. , Krumkacheva O.A. , Ivanov M.Y. , Prikhod'ko S.A. , Adonin N.Y. , Tormyshev V.M. , Bowman M.K. , Fedin M.V. , Bagryanskaya E.G.
Pulse EPR of Triarylmethyl Probes: A New Approach for the Investigation of Molecular Motions in Soft Matter
Journal of Physical Chemistry B. 2018. V.122. N36. P.8624-8630. DOI: 10.1021/acs.jpcb.8b07714 WOS Scopus РИНЦ OpenAlex

Published online:	Aug 23, 2018
Published print:	Sep 13, 2018

Web of science:	WOS:000444922800013
Scopus:	2-s2.0-85053205753
Elibrary:	41777770
OpenAlex:	W2888198194

DB	Citing
Web of science	15
Scopus	16
OpenAlex	16