Accession Number : AD0709403

Title :   MULTIPLE RESONANCE TECHNIQUES IN THE STUDY OF THE MAGNETIC, RADIATIVE AND NONRADIATIVE PROPERTIES OF THE TRIPLET STATE.

Descriptive Note : Technical rept.,

Corporate Author : CALIFORNIA UNIV LOS ANGELES DEPT OF CHEMISTRY

Personal Author(s) : El-Slayed,M. A.

Report Date : JUL 1970

Pagination or Media Count : 40

Abstract : A physical picture of the origin of the zero field splittings and levels of the three zero field spin states of aromatic molecules is given. At very low temperatures (<2K), the spin-lattice relaxation processes between these levels can be frozen. Under these conditions, the emission properties of the lowest triplet state are the sum, rather than the population-weighed average, of those of the different emitting zero field levels. Since the rates of pumping and deactivating the different zero field levels of the lowest triplet states are most likely to be unequal, the steady-state population of these three levels becomes unequal, i.e., a state of spin alignment in one molecular direction can be produced. A number of phosphorescence-microwave multiple resonance experiments can thus be carried out from which important information can be determined. (Author)

Descriptors :   (*PHOSPHORESCENCE, ELECTRON TRANSITIONS), MOLECULAR ENERGY LEVELS, RELAXATION TIME, MICROWAVES, SPINNING(MOTION), AROMATIC COMPOUNDS

Subject Categories : Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE