UV Absorption Cross Sections of Gaseous Dimethylnitramine
Abstract
The ultraviolet absorption spectrum of gas phase, room temperature, dimethylnitramine is reported. The spectrum contains two distinct features whose maximums occur at 193 nm (6.4 eV) and 230 nm (5.4 eV). The oscillator strength for the transition which peaks at 230 nm is determined to be 0.14 + or - 0.03. Absorption cross section at selected wavelengths between 185 nm and 325 nm have been extracted employing Beer-Lambert's law. These results are important in interpreting studies of UV photodissociation of this molecule. Dimethylnitramine (DMNA), (CH3)2N-NO2, has been extensively studied as a simple analog expected to exhibit some of the reactions important in cyclic nitramine decomposition. Although many studies include its gas phase dissociation following excitation with UV radiation, a reference for its gas phase UV absorption cross sections has not been established. The purity of the DMNA sample was determined to be 95% from mass spectrometric and IR absorption analysis. Two different systems were used to obtain absorption cross section measurements. In the first system, UV absorption spectra were recorded with a Perkin-Elmer, Lambda Array 3840, Spectrophotometer. The measurements were made in a static cell which consisted of a 10-cm long pyrex tube capped with LiF windows. A high vacuum, stainless steel, gas handling system equipped with a capacitance manometer (MKS, Model 222B) was employed for sample preparation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1991
- Accession Number
- ADA242663
Entities
People
- Michael J. McQuaid
- Rosario C. Sausa
Organizations
- Ballistic Research Laboratory