Abstract: Chemical stability of primary radical cations (RCs) generated in irradiated matter determines substantially the radiation resistance of organic materials. Transformations of the RCs of the glyme molecules, R(-O-CH2-CH2)(n)O-R (R = CH3, n = 1-4) has been studied on the nanosecond time scale by measuring the magnetic field effects in the recombination fluorescence from irradiated liquid solutions of the glymes. In all cases, the RCs observed were different from that expected for the primary ones and revealed very similar hyperfine couplings independent of the poly(ethylene oxide) chain length and of the substitution of terminal methyl groups by C2H5 or CH2CH2Cl, as has been shown with diglyme as an example. Quantum chemical analysis of possible chemical transformations for the monoglyme RC as a model system allowed us to discover the reaction pathway yielding the methyl vinyl ether RC. The pathway involves intramolec-ular proton transfer followed by C-O bond cleavage. Only one (-O-CH2-CH2-O-) fragment is involved in this transformation, which is nearly barrierless due to the catalytic effect of adjacent glyme molecules. The rapid formation of the methyl vinyl ether RC in the irradiated monoglyme was confirmed by the numerical simulation of the experimental curves of the time-resolved magnetic field effect. These findings suggest that the R'-O-CH=CH2 center dot+ formation is a typical decay pathway for the primary RCs in irradiated liquid glymes.

Cite: Taletskiy K.S. , Borovkov V.I. , Schegoleva L.N. , Beregovaya I.V. , Taratayko A.I. , Molin Y.N.
Radical Cationic Pathway for the Decay of Ionized Glyme Molecules in Liquid Solution
Journal of Physical Chemistry B. 2015. V.119. N45. P.14472-14478. DOI: 10.1021/acs.jpcb.5b06086 WOS Scopus

Dates:

Published online:	Oct 29, 2015
Published print:	Nov 12, 2015

Identifiers:

Web of science	WOS:000364796500014
Scopus	2-s2.0-84946854566
OpenAlex	W2469457487

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