Infrared Intensities of Liquids XIV: Accurate Optical Constants and Molar Absorption Coefficients between 4800 and 450 cm−1 of Chlorobenzene at 25°C from Spectra Recorded in Several Laboratories

Accurate infrared absorption intensities of liquid chlorobenzene at 25°C are presented. Their accuracy was estimated from the agreement between the intensities measured by different spectroscopists using different instruments in different laboratories and by different spectroscopists using the same instrument in the same laboratory. The spectra from different spectroscopists have been averaged, unweighted, to give intensity spectra of chlorobenzene that are presented as the best available. The results are presented as graphs and tables of the molar absorption coefficient, Em (ν˜), and the real and imaginary refractive indices, n(ν˜) and k(ν˜), between 4800 and 450 cm−1. The peak heights and the areas under the bands in the absorption index (imaginary refractive index) spectrum are reported, as are areas under the molar absorption coefficient spectrum. Absorption index, k(ν˜), and molar absorption coefficient, Em (ν˜), values are believed accurate to an average ±2.4% at the peaks of bands with kmax > 0.002 and ±3.3% at the peaks of bands with kmax < 0.002. In the baseline k(ν˜) is accurate to ∼ ±5% above 3000 cm−1 and ∼ ±2.5% below 3000 cm−1. The areas under bands in k(ν˜) and Em (ν˜) spectra for which kmax > 0.002 are accurate to ±1.3% on average. The real refractive index, n(ν˜), values are believed to be accurate to ±0.2%.

Subpicosecond laser spectroscopy: strong field effects on molecular photophysics and dynamics

The possible role of strong field effects is discussed in the context of picosecond relaxation and reaction in polyatomic systems. The picosecond pulse diagnostics from an argon-ion synchronously pumped dye laser are then outlined in terms of cavity detuning and laser pumping parameters. A profile of auto-correlation data on ensemble-averaged pulses and streak camera data on single pulses is presented, from which the domain of stable, single pulse operation can be deduced. Finally data are presented on the photoionization and energy relaxation of pyrene in alcohols and micelles, and for the reorientational dynamics of liquid chlorobenzene, which illustrate different consequences of strong field phenomena in dense media.