@Article{B501041A,
author ="Desyatnyk, O. and Pszczolkowski, L. and Thorwirth, S. and Krygowski, T. M. and Kisiel, Z.",
title  ="The rotational spectra{,} electric dipole moments and molecular structures of anisole and benzaldehyde",
journal  ="Phys. Chem. Chem. Phys.",
year  ="2005",
volume  ="7",
issue  ="8",
pages  ="1708-1715",
publisher  ="The Royal Society of Chemistry",
doi  ="10.1039/B501041A",
url  ="http://dx.doi.org/10.1039/B501041A",
abstract  ="The rotational spectra of anisole and of benzaldehyde were investigated in supersonic expansion at frequencies up to 41 GHz{,} and at room temperature in the millimetre-wave region{,} from 170 to 330 GHz. Accurate spectroscopic constants for the parent isotopomers in the ground vibrational state and for the first excited torsional state were determined for both molecules. The supersonic expansion spectrum allowed measurement{,} in natural abundance{,} of all singly substituted 13C isotopomers{,} as well as of the 18O isotopomer for both anisole and benzaldehyde. The rotational constants were used to determine the rs and the rm(1) gas-phase geometries{,} which are found to be consistent with prediction of bond length alternation in the phenyl ring induced by the asymmetric substituent. Stark measurements were made on the supersonic expansion spectrum resulting in electric dipole moment determination{,} |[small mu ]a| = 2.9061(22) D{,} |[small mu ]b| = 1.1883(10) D{,} [small mu ]tot = 3.1397(24) D for benzaldehyde and |[small mu ]a| = 0.6937(12) D{,} |[small mu ]b| = 1.0547(8) D{,} [small mu ]tot = 1.2623(14) D for anisole. During the investigation it was found that use of a carrier gas mixture consisting of 30% Ar in He carries significant advantages for studies of weak lines{,} and pertinent experimental details are reported."}