title: Photoacoustic spectra and modes of vibration of TNT and RDX at CO2 laser wavelengths.
abstract: IR spectra in the 'Finger Print' spectral range has great importance in qualitative and quantitative analysis of explosives like trinitrotoluene (TNT) and cyclotrimethyltrinitramine (RDX). Highly resolved IR bands of these compounds have been recorded in the 9.6 and 10.6 microm regions of CO2 laser. TNT and RDX are large molecules each having 21 atoms and it is very difficult to assign the modes of vibrations by comparison with those in other molecules making the vibrational assignments of observed bands a difficult task. The ab initio quantum chemical calculation is used for determining the molecular geometries and modes of vibration of these molecules with a view to assign their normal modes in the high resolution vibrational photoacoustic spectra. These assignments are very reliable in view of the good agreement between the observed and calculated frequencies of deuterated TNT.
authors.affiliation: Department of Physics, Banaras Hindu University, Varanasi 221 005, India.
authors.forename: R L
authors.initials: RL
authors.lastname: Prasad
authors.forename: R
authors.initials: R
authors.lastname: Prasad
authors.forename: G C
authors.initials: GC
authors.lastname: Bhar
authors.forename: S N
authors.initials: SN
authors.lastname: Thakur
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry*; D007834:Lasers; D013055:Spectrophotometry, Infrared; D014227:Triazines / Q000737:chemistry*; D014303:Trinitrotoluene / Q000737:chemistry*
chemical_list: D014227:Triazines; D014303:Trinitrotoluene; D002245:Carbon Dioxide; C009160:cyclonite