  The possibility of using time-resolved vibronic spectroscopy for spectral
analysis of mixtures of chemical compounds with similar optical properties,
when traditional methods are inefficient, is demonstrated by using the method
of computer simulation. The analysis is carried out by the example of molecules
of a series of polyenes (butadiene, hexatraene, octatetraene, decapentaene, and
decatetraene), their various cis- and trans-rotational isomers, and
phenyl-substituted polyenes. Ranges of relative concentrations of molecules
similar in their spectral properties, where reliable interpretation of
time-resolved spectra of mixtures and both qualitative and quantitative
analyses are possible, are determined. The use of computer simulation methods
for oprimizing full-scale experiments in femtosecond spectroscopy is shown to
hold much promise.
