Using both a cavity and a broadband microwave spectrometers, the microwave spectrum of the sugar alcohol 1,3-propanediol (CH2OHCH2CH2OH) has been measured over the frequency range 6.7 GHz to 25.4 GHz. Two conformers of 1,3-propanediol have been assigned and ab initio electronic structure calculations of the eight lowest energy forms have been calculated. Both conformers exhibit tunneling between equivalent structures and split the a-type transitions by about 11 MHz for conformer I and 78 MHz for conformer II. The tunneling pathways have been examined with ab initio calculations. Stark effect measurements were carried out on the lowest energy conformer to provide accurate determinations of the dipole moment components.
Citation: Journal of Physical Chemistry A
Pub Type: Journals
Ab Initio Structure, Dipole Moment, Microwave Spectrum, Propanediol, Rotational Spectrum, Tunneling