Inverse light-induced drift of methanol and CH3F molecules

A light-induced drift (LID) of methanol molecules has been observed for the first time. Measurements were made using an inverse variant of the LID where the concentration of absorbing particles was considerably higher than that of the buffer particles. An investigation was made of the separation of isotopic modifications of methanol molecules. The theoretical relationships used to describe the inverse LID were checked using the inverse LID of CH₃F molecules. It was found that the transport frequency of collisions between methanol molecules increased by 1.3 ± 0.2% when the ν₅ vibrational mode was excited.