Accession Number : AD0717155

Title :   Quenching of Naphthalene Luminescence by Oxygen and Nitric Oxide.

Descriptive Note : Rept. for Mar 69-Aug 70,

Corporate Author : AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS

Personal Author(s) : Jones,Peter F. ; Siegel,Seymour

Report Date : 28 DEC 1970

Pagination or Media Count : 34

Abstract : The quenching of naphthalene-h8 and naphthalene-d8 luminescence by O2 and NO in the absence of molecular diffusion was investigated. By measurement of the dependence of fluorescence and phosphorescence yields and lifetimes on quencher concentration, it was possible to separate the effects of singlet and triplet electronic state quenching and to determine the critical quenching radii R(o). No static quenching of naphthalene fluorescence was observed for O2 concentrations of up to 0.25 M. Conversely, the concentration dependence of naphthalene-h8 and naphthalene-d8 triplet state quenching by O2 is in excellent agreement with the Perrin formula. The rate constant for naphthalene triplet state quenching by O2 decreases upon the deuteration of naphthalene. The concentration dependence of naphthalene-h8 and naphthalene-d8 fluorescence quenching by NO is in excellent agreement with the Perrin formula. Possible causes for the greater efficiency of fluorescence quenching by NO than by O2 are discussed. The value of R(o) for naphthalene triplet state static quenching by NO cannot be determined with certainty because of the possibility that the excited singlet state is quenched directly to the ground state. (Author)

Descriptors :   (*NAPHTHALENES, *QUENCHING(INHIBITION)), (*LUMINESCENCE, NAPHTHALENES), DEUTERIUM COMPOUNDS, FLUORESCENCE, PHOSPHORESCENCE, OXYGEN, NITROGEN OXIDES, ELECTRON TRANSITIONS

Subject Categories : Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE