Spectroscopy of condensed matter

EPR spectroscopy and partial orientation ordering of formyl radicals stabilized in CO and Ar polycrystals at helium temperatures

Yu. A. Dmitriev

Ioffe Institute, St. Petersburg, Russia

Abstract: EPR spectra of formyl radicals DCO and HCO stabilized in solid CO and Ar, respectively, were recorded and investigated. The radicals were obtained by gas condensation on a substrate at the liquid helium temperatures. Partial orientation ordering of the radicals in the polycrystal matrices was revealed using spectrum simulation. In the carbon monoxide solid, the C=O bond of the formyl radical was directed parallel to the deposition surface of the substrate and, at the same time, perpendicular to a plane formed by the gas flows. In the Ar matrix, such a preferred direction was the normal to the deposition surface. Thus, observed for the first time with the stabilized formyl radicals, the partial ordering was estimated to be 4% and 17%, for the DCO/CO and HCO/Ar systems, respectively.

Keywords: electron paramagnetic resonance, matrix isolation, cryodeposits, formyl radical, powder spectrum, partial orientation ordering.

Received: 15.06.2023
Revised: 05.08.2023
Accepted: 21.10.2023

DOI: 10.61011/OS.2023.10.56886.5321-23

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