Accession Number : AD0610102

Title :   ELECTRICAL AND MAGNETIC PROPERTIES OF ORGANIC SOLIDS.

Descriptive Note : Final rept. for Sep 62-Nov 64,

Corporate Author : ARIZONA UNIV TUCSON DEPT OF CHEMISTRY

Personal Author(s) : Tollin,Gordon

Report Date : 27 NOV 1964

Pagination or Media Count : 40

Abstract : The study of the E.P.R. spectra of the isoalloxazine semiquinones was extended to neutral and basic pH. The data demonstrate that the unpaired spin density distribution of the neutral radical is identical to that of the acid form, thus showing that the proton added to the molecule in going from neutral to acid pH does not interact with the unpaired electron. Flavin-phenol complexes in neutral solution were found to have a 1:1 flavin:phenol ratio, while crystalline complexes obtained from such solutions display a 1:2 ratio. Stability constants of the complexes range roughly from 1 to 250. Neutral complexes are much more stable than acid complexes. Charge transfer does not contribute significantly to the stabilization of the acid complexes. It was found that hydroiodic acid can reduce isoalloxazine derivatives to the semiquinone level. The electrical and magnetic properties of single crystals of 1:1 charge transfer complexes of protonated flavins and phenols were investigated. EPR results indicate that complete electron transfer processes can occur at lattice imperfection sites which are produced either during the crystallization process or by removal of solvent from already-formed crystals. The unpaired spins so produced behave as localized, doublet state, free radicals.

Descriptors :   (*SEMICONDUCTORS, ORGANIC MATERIALS), (*ANTHOXANTHIN PIGMENTS, PHYSICAL PROPERTIES), (*PHENOLS, PHYSICAL PROPERTIES), COMPLEX COMPOUNDS, QUINONES, AZINES, ELECTRICAL PROPERTIES, MAGNETIC PROPERTIES, PH FACTOR, NUCLEAR MAGNETIC RESONANCE, ABSORPTION SPECTRA, NUCLEAR SPINS, CRYSTALS, STABILITY, ATOMIC ENERGY LEVELS, ELECTRON TRANSITIONS, PHOTOCHEMICAL REACTIONS

Distribution Statement : APPROVED FOR PUBLIC RELEASE