Spin-locking in concentration-narrowed OD ESR spectra

• Published in: Chemical physics Vol. 138; no. 1; pp. 173 - 178
• Main Authors: Koptyug, A.V., Saik, V.O., Animisov, O.A., Molin, Yu.N.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.1989; Elsevier
• Subjects: Atomic and molecular physics; Chemistry; Electron resonance and relaxation; Exact sciences and technology; Fysikalisk kemi; Kemi; Kinetics; Kinetik; Molecular properties and interactions with photons; NATURAL SCIENCES; NATURVETENSKAP; Physical chemistry; Physics; Chemical solution; Hydrocarbon; Isotopic species; Experimental study; Condensed benzenic compound; Naphthalene; Spectral line profile; Concentration effect; Benzenic compound; Molecular aggregation; EPR spectrum; Singlet triplet transition; Magnetic field; Diphenyl; Organic compounds
• ISSN: 0301-0104; 1873-4421
• DOI: 10.1016/0301-0104(89)80266-6

The effect of spin-locking under the action of a resonance rf field of large amplitude has been observed in the optically detected ESR spectra (OD ESR) of radical-ion pairs both in strong and weak magnetic fields. “Hampering” of singlet-triplet transitions occurs for concentrations of aromatic acceptors in non-polar solutions at room temperature from 10 −4 to 1 M. It is proposed that in spite of strong concentration narrowing OD ESR signals are inhomogeneously broadened. This can be due to neutral molecule-radical-cation aggregate formation.