International Conference Physics.SPb/2025
Spectroscopy and physics of atoms and molecules

Relative orientation dynamics of stabilized CH$_3$ radicals and matrix CH$_4$ molecules in solid methane in 1.4–35 K temperature region

Yu. A. Dmitriev

Ioffe Institute, St. Petersburg

Abstract: Results are presented on CH$_3$ radical stabilization in solid CH$_4$ matrix from the gas phase and their study by EPR. In the first series of experiments, the samples are obtained by deposition on a substrate at $T_{\mathrm{dep}}$ = 4.2 K and studied in temperature range $T_{\mathrm{rec}}$ = 1.4 – 4.2 K. In the second series of the experiments, the relevant temperatures are: $T_{\mathrm{dep}}$ = 15 – 17 K, $T_{\mathrm{rec}}$ = 6.3 – 35.2 K. The relative intensity of the forbidden electron-proton transitions is measured versus microwave power and the sample temperature. The experimental result analysis testify to existence of two temperature regions with different degrees of correlation between the radical and matrix molecules orientation motion.

Keywords: electron paramagnetic resonance, matrix isolation, methyl radical, solid methane, molecular rotation.

Received: 28.04.2025
Revised: 03.07.2025
Accepted: 24.10.2025

DOI: 10.61011/OS.2025.10.61936.7915-25