Infrared diode laser spectroscopy

Infrared diode laser spectroscopy has been used for the measurement of hydrocarbon and CO concentrations in exhaust (13, 14, 15). The adsorption path length, and thus the absorption cell volume, required for hydrocarbon measurement is rather large, limiting the time-resolution of the measurement. The absorption path length required for CO measurement, however, is relatively short and approximately equal to the diameter of a standard exhaust pipe. This allows CO to be measured with high time-resolution by an infrared laser beam passed through an... 

Sell, J. A. Herz, R. K. Monroe, D. R. "Dynamic Measurement of Carbon Monoxide Concentrations in Automotive Exhaust Using Infrared Diode Laser Spectroscopy" SAE Paper No. 800463, 1980. 

Infrared diode laser spectroscopy, 46 119, 148 Infrared emission, transition,-metal ions, 35 334-335... 

C. Yamada and E. Hirota, Phys. Rev. Lett., 56, 923 (1986). Detection of the Silyl Radical SiH3 by Infrared Diode-Laser Spectroscopy. 

CIRDLS = infrared diode laser spectroscopy ES = electronic spectroscopy, spectra with resolved vibrational structure MW = microwave spectroscopy force field calculations denote harmonic frequencies obtained on the basis of combined analysis of electron diffraction and vibrational spectroscopy data. 

Infra-red chemiluminescence has been used to measure the vibrational state distributions of CO2 formed by reaction on Pt and Pd surfaces [45-50]. While the detection sensitivity of infrared chemiluminescence does not approach that of LIF or REMPI, it is an attractive way to probe molecules such as CO2 where there is substantial vibrational excitation and REMPI schemes are not available. In some cases Doppler measurement of the translational energy release can be achieved, giving direct information on the translational energy release of vibrationally excited C02 [45]. Recently infrared diode laser spectroscopy has been used to detect vibrationally excited CO2 from CO oxidation over... 

In our work on CO2-HX structures, tunable infrared diode laser spectroscopy was used to obtain geometries for X = F, Cl, and Br, using the CO2 asymmetric stretch chromophore [34], Both CO2-HF and CO2-HCI displayed the clear signatures of the linear equilibrium geometries that had been established previously [35, 36]. On the other hand, the C02-HBr spectrum showed that this complex is very asymmetric, which came as a surprise. We had originally assumed that C02-HBr was linear, by analogy with CO2-HF and COj-HCl. However, it is not. The observed C02-HBr spectra indicate a broadside inertial structure, with an u-axis moment of inertia close to that of uncomplexed CO2. Figures 11 and 12 show representative spectra that... 

Relative CO2-HCI and C02-HBr concentrations were measured under conditions similar to those used in the photoinitiated reactions, but in a completely separate apparatus that used pulsed slit nozzle expansions and tunable infrared diode laser spectroscopy. This was achieved by recording fully rotationally resolved CO2-HXIR absorption spectra using the CO2 asymmetric stretch chromophore, as described in Section III.A. The rotational distributions fit temperatures quite well, usually 3K. Rotational partition functions were calculated for the measured rotational temperatures and the areas under the absorption lines recorded for all transitions. From this, relative concentrations were determined. Details are available elsewhere [139, 140]. 

Valuable information on the kinetics and mechanism of CF3 + N02 comes from the experimental and theoretical study by Pagsberg et al,226 The experiments, performed using time-resolved infrared diode laser spectroscopy, were supported by ab initio calculations to provide insight into the potential energy surface of the reaction system. The reaction was initiated by pulse radiolysis of Ar/SF6/CF3I mixtures. The abstraction reaction of the iodine atom from CF3I by fluorine atoms leads to the formation of CF3 radicals. The reactions... 

The spectroscopy of FCO is reasonably well understood. The first infrared spectrum of FCO formed in a CO matrix was obtained by Milligan and co-workers [175]. Three peaks due to FCO were assigned to the three fundamentals. Jacox [176] reexamined the spectra of FCO using isotopic substitution to refine the vibrational assignment of FCO. The CO stretch mode for FCO occurs at 1861 cm" (Vj), the FCO bend is at 628 cm", and the CF stretch occurs at 1026 cm" Nagai and co-workers [177] used infrared diode laser spectroscopy to obtain a high-resolution spectra of the CO and CF stretching modes. There have been several studies of the ultra-... 

Mar Marr, A.J., Sears, T.J., Davies, P.B. High-Resolution Infrared Diode Laser Spectroscopy of CBr, J. Mol. Spectrose. 184 (1997) 413 33. 

O40ha Ohashi, N., Fujitake, M. Near-infrared diode laser spectroscopy of free radicals, Spectrochim. Acta A 60 (2004) 3277-3284. 

Arnesen SP, Seip HM (1966) Studies on failure of first Bom approximation in electron diffraction molybdenum- and tungsten hexacarbonyl. Acta Chem Scand 20 2711-2727 Martinez A, Morse MD (2006) Infrared diode laser spectroscopy of jet-cooled NiCO, Ni(CO)3( CO), and Ni(CO)3(C 0). J Chem Phys 124 124316... 

Table 5-43. Other spectroscopic methods Tlinable infrared diode laser spectroscopy.

TUnable infrared diode laser spectroscopy Reid 1978 2 Method 404... 

Pagsberg P, Ratajczak E, SUlesen A and Lotaika Z (1994) Kinetics and thermochemistry of the reversible gas phase reaction HONO + NHj — H3N-HONO studied by infrared diode laser spectroscopy. Chemical Physics Letters 227 6-12. 

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