Internal energy distributions from nitrogen dioxide fluorescence. 1. Cumulative sum method

Journal Article · Thu Sep 30 00:00:00 EDT 1993 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100141a004· OSTI ID:5424640

Johnston, H S; Miller, C E; Oh, B Y; Patten, Jr, K O; Sisk, W N ^[1]

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1. Univ. of California, Berkeley, CA (United States) Lawrence Berkeley Lab., CA (United States)

This article describes a method of obtaining information about the internal energy (E) distribution of a fluorescing population of nitrogen dioxide, NO[sub 2]*, from its dispersed spectrum between 400 and 840 nm. We show that two fluorescing populations of the same average energy but different energy spread give statistically significant differences in their observed cumulative sum spectra, although the differences are small. Broadly spread distributions of NO[sub 2]* internal energy are produced by photolysis of RNO[sub 2] molecules and by collisional deactivation of monoenergetically excited NO[sub 2]. The cumulative sum fluorescence spectrum from a broadly distributed internal energy population is represented as a weighted combination of monoenergetically excited cumulative sum fluorescence spectra. A cumulative sum spectrum utilizes all of the data, is positive and single valued, and smoothly, monotonically increases with decreasing observation energy. By differentiation of the cumulative sum spectrum, the original spectrum is recovered undistorted. Unlike a structured monoenergetic fluorescence spectrum, the cumulative sum is well approximated by a simple algebraic expression, I(E,X), where E is the internal energy of NO[sub 2]* and X are the photon energies of the observed spectrum. 14 refs., 18 figs., 3 tabs.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5424640
• Journal Information: Journal of Physical Chemistry; (United States), Vol. 97:39; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
NITROGEN DIOXIDE
FLUORESCENCE SPECTROSCOPY
EXCITED STATES
EXPERIMENTAL DATA
FLUORESCENCE
LEAST SQUARE FIT
MATRICES
PHOTOLYSIS
THEORETICAL DATA
VIBRATIONAL STATES
CHALCOGENIDES
CHEMICAL REACTIONS
DATA
DECOMPOSITION
EMISSION SPECTROSCOPY
ENERGY LEVELS
INFORMATION
LUMINESCENCE
MAXIMUM-LIKELIHOOD FIT
NITROGEN COMPOUNDS
NITROGEN OXIDES
NUMERICAL DATA
NUMERICAL SOLUTION
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
SPECTROSCOPY
400201* - Chemical & Physicochemical Properties
400500 - Photochemistry