ELECTRON SPIN RESONANCE STUDIES OF A WEAKLY COUPLED BIRADICAL. Technical Report No. 37

Technical Report · Tue Nov 29 04:00:00 EST 1960

OSTI ID:4082860

Anderson, D H; Gutowsky, H S; Sandin, R B

Electron spin resonance, including its temperature dependence, was studied in several solid salts derived from theta , alpha , beta , beta - tetrakis- (4-dimethylaminophenyl)-ethylene (I). The paramagnetism appears to result form thermal excitation to low-lying triplet electronic states in which the unpaired electrons are only weakly coupled. Excitation energies of 4.5 and 8.6 kcal/mole are found for the I-diiodide and the I-dinitrate, respectively, the former value being confirmed by an absolute intensity measurement. The line widths are only 1 to 3 gauss in the solids even though the concentration of free radicals is very small. It is suggested that the averaging out of hyperfine and electron dipoledipole splittings results from delocalization of the unpaired electrons and from exchange interactions that may be aided by the "diffusion" of the paramagnetic species that results from the thermal excitation and deactivation. This implies that the solids are semiconductors, which was found to be the case from resistivity as a function of temperature measurements on the I-diiodide, the stablest of the derivatives. (auth)

• Research Organization: Illinois. Univ., Urbana
• NSA Number: NSA-15-010927
• OSTI ID: 4082860
• Report Number(s): NP-9842
• Country of Publication: United States
• Language: English

Related Subjects

BINDING ENERGY
CHEMISTRY
ELECTRIC MOMENTS
ELECTRONS
FREE RADICALS
HYPERFINE STRUCTURE
IODIDES
MAGNETISM
MEASURED VALUES
NITRATES
PARAMAGNETISM
RESONANCE
SALTS
SEMICONDUCTORS
SOLIDS
SPIN
TEMPERATURE