Accession Number : AD0716577
Title : Excited Electronic States of Nitroaromatic Compounds.
Descriptive Note : Memorandum rept.,
Corporate Author : BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD
Personal Author(s) : May,Ingo W. ; Kelso,John R.
Report Date : OCT 1970
Pagination or Media Count : 37
Abstract : Experimental triplet lifetimes have been obtained for 1-nitronaphthalene (48 msec) and 1,4-dinitronaphthalene (21 msec) in EPA solutions at 77K by luminescence spectroscopy and electron spin resonance. Both techniques have yielded identical lifetimes within experimental error. Emission spectra have been determined and corrected for nonlinear monochromator and photomultiplier response. In addition mean zero-field splitting parameters have been determined for 1-nitronaphthalene (D* = 0.0893/cm) and 1,4-dinitronaphthalene (D* = 0.0818). These values indicate that the excited triplet state for these triplet (pi*, n) states is no longer localized within the nitro group which implies that electronic charge is transferred from the nitro group into the aromatic ring. This represents the first definitive observation of any triplet(pi*, n) state by spin resonance techniques. (Author)
Descriptors : (*ORGANIC NITROGEN COMPOUNDS, *MOLECULAR ENERGY LEVELS), (*PHOSPHORESCENCE, ORGANIC NITROGEN COMPOUNDS), (*ELECTRON PARAMAGNETIC RESONANCE, MOLECULAR ENERGY LEVELS), RELAXATION TIME, ELECTRON PARAMAGNETIC RESONANCE, ELECTRON TRANSITIONS, NAPHTHALENES, ULTRAVIOLET SPECTRA, VISIBLE SPECTRA
Subject Categories : Organic Chemistry
Atomic and Molecular Physics and Spectroscopy
Distribution Statement : APPROVED FOR PUBLIC RELEASE