Laboratory spectroscopic studies of reactive intermediates relevant to the combustionl

Abstract

The goal of this thesis is to describe studies about molecular species invertigated by spectroscopic methods which are relevant to the safety sciences – it means first of all chemistry of combustion. The first chapter called “Microwave spectroscopy of the H212C16O” deals with molecule of formaldehyde studied by microwave spectroscopic technique, namely rotational transitions within excited vibrational states in the millimeter-wave and submillimeter-wave region. This work has been motivated by the atmospheric and astrophysical importance of formaldehyde (H2CO). The main aid of this study is to complete the already existing list of rotational transitions within the ground vibrational state by a list of transitions within the four first excited 21, 31, 41 and 61 vibrational states, to help the detections of this species by microwave or millimeterwave techniques. In the second chapter called “Photoacoustic spectroscopy of the C7H14O2” are interpretated absorption spectra of molecule of n-pethylacetate studied by photoacoustic detection (PAS) for concentration analysis. The absorption spectra of gaseous n-penthylacetate has been investigated by means of Fourier transform infrared spectroscopy (FTIR) as well as CO2-laser photoacoustic spectroscopy (PAS) for simulation of the dispersion of a nerve agent (sarin) within a modeled atmospheric boundary layer. Three CO2-laser emission lines has been used for photoacoustic detection of n-penthylacetate with detection limit in the range of 1-3 ppm. And the last chapter called “Infrared spectroscopy of XCN+” deals with molecular ions from CN• radical family, especially halogen-cyanide radical cations XCN+ (X = Br, I, Cl) studied by use of tunable diode-laser (TDL) infrared spectroscopic technique. Radical cation ICN+ has been studied theoretically and also experimentally by means of this method as well as by means of the FTIR spectroscopy in the discharge plasma as a simulation of exothermic medium. Series of the lines with periodic wavenumber distances have been detected. It is supposed that they indicate new generated species that has been proved by Loomis Wood analysis. Furthermore the FTIR spectra have been recorded and individual bands have been assigned to determinate the chemical composition of the newly generated species at discharge conditions.