INFRARED OPTICAL AND DIELECTRIC CONSTANTS OF LIQUID ALIPHATIC ALCOHOLS AND THE MAGNITUDE OF THE CHANGE IN MOLECULAR DIPOLE MOMENT DURING THE OH STRETCHING VIBRATION

Author Institution: Department of Chemistry, University of Alberta; Department of Chemistry, University of Alberta; Anorganisch Chemisches Institut der, Universitat HeidelbergThe CIRCLE attenuated total reflection FTIR accessory is used to measure infrared optical and dielectric constants and the infrared conductivity, with a Bruker IFS 113V FTIR spectrometer. The method, calculations, and programs (written for the Bruker Aspect 2000 computer in Pascal with some assembly language routines) will be described. For condensed phases it is the infrared conductivity, not the Beer-Lambert coefficient, that provides the simple measure of absorption, i.e. of $(\partial \mu / \partial Q)^{2}$, that the Beer-Lambert coefficient provides for a gas. The infrared optical and dielectric constants and the infrared conductivity of liquid aliphatic alcohols will be presented, including the evidence that the magnitude of the dipole moment change during an O-H stretching vibration is independent of the alcohol within $\pm 2%$ for liquid $CH_{3} OH, C_{2}H_{5} OH, n-C_{3}H_{7}OH ,n-C_{4}H_{9}OH$ and $n-C_{7}H_{15}OH$