Laser resonance absorption flash kinetic

The gas-phase UV spectrum of GeMe2 generated from two different precursors has been recorded by laser resonance absorption flash kinetic spectroscopy106. The identity of the germylene was supported by chemical trapping experiment and by analysis of the stable end products of the decomposition of the chosen precursors. 

LRAFKS laser resonance absorption flash kinetic spectroscopy... 

SiH2 is a highly reactive species which may undergo fast insertion reactions into o bonds and addition reactions to n bonds. The available work on the elementary reactions of SiH2 up to 1994 has been reviewed in detail by Jasinski et al. Because of its intense and well-resolved Bi <— Ai electronic absorption in the visible spectrum,SiH2 is easily detected with high sensitivity by laser-induced fluorescence, laser resonance absorption flash kinetic spectroscopy, or cavity ring-down spectroscopy. These techniques... 

Kinetics of reactions of Fe(CO), (x = 2, 3, 4) with CO. 547 Co-ordinatively unsaturated intn carbonyls generated by exclmer laser flash photolysis of FelCO) and monitored using CW CO laser resonance absorption Competition between photofragmentation and photo- 548 ionization of jet-cooled FefCO) used to obtain excited-state lifetimes in the wavelength range 290—310 nm. 

Experimental Techniques A absorption CIMS = chemical ionization mass spectroscopy CK = competitive kinetics DF discharge flow EPR = electron paramagnetic resonance FP = flash photolysis FT = flow tube FTIR Fourier transform intra-red GC = gas chromatography, UF = laser induced fluorescence LMR = laser magnetic resonance MS = mass spectroscopy PLP = pulsed laser photolysis SC = smog chamber SP = steady (continuous) photolysis UVF = ultraviolet flourescence spectroscopy... 

The abbreviations used for techniques are DF-RF discharge flow-resonance fluorescence DF-RA discharge flow-resonance absorption DF-ESR discharge flow-esr detection DF-LMR discharge flow with laser magnetic resonance detection of OH DF-MS discharge flow-mass spectrometry FP-KS flash photolysis-kinetic spectroscopy FP-RA flash photolysis-resonance absorption FP-RF flash photolysis-resonance fluorescence MPS modulation-phase shift ... 

The conditions which determine whether flash photolysis can be used to smdy a given chemical system are (i) a precursor of the species of kinetic interest has to absorb light (normally from a pulsed laser) (ii) this species is produced on a timescale that is short relative to its lifetime in the system. Current technical developments make it easy to study timescales of nanoseconds for production and analysis of species, and the use of instrumentation with time resolution of picoseconds is already fairly common. In certain specific cases, as we will see in the last part of this chapter, it is possible to study processes on timescales greater than a few femtoseconds. Once the species of interest has been produced, it is necessary to use an appropriate rapid detection method. The most common technique involves transient optical absorption spectroscopy. In addition, luminescence has been frequently used to detect transients, and other methods such as time-resolved resonance Raman spectroscopy and electrical conductivity have provided valuable information in certain cases. 

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