title: Electronic and vibrational transition moment directions in 7-dimethylamino-3-methyl-N-methyl-d3-4-phenylethynylcarbostyril.
abstract: We report the synthesis and photophysical characterization of 7-dimethylamino-3-methyl-N-methyl-d(3)-4-phenylethynylcarbostyril, a chromophore of interest as a rotator in surface-mounted molecular rotors. Measurement of UV-vis absorption and fluorescence spectra, steady state fluorescence and excitation anisotropy, and linear dichroism in the IR and UV-vis permitted a determination of absolute vibrational and electronic transition moment directions in this previously unreported chromophore. The first singlet-singlet absorption and fluorescence are polarized perpendicular to the axle of the rotator. Density functional theory calculations of electronic excitation and vibrational frequencies gave results in very good agreement with those observed. Calculated IR transition moment directions showed rather poor agreement with experiment.
authors.affiliation: Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States.
authors.forename: Deborah L
authors.initials: DL
authors.lastname: Casher
authors.forename: Lukáš
authors.initials: L
authors.lastname: Kobr
authors.forename: Josef
authors.initials: J
authors.lastname: Michl
mesh_terms: D004583:Electrons; D008744:Methylamines / Q000138:chemical synthesis / Q000737:chemistry*; D015394:Molecular Structure; D011789:Quantum Theory; D015363:Quinolones / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism; D014732:Vibration
chemical_list: C569649:7-dimethylamino-3-methyl-N-methyl-D3-4-phenylethynylcarbostyril; D008744:Methylamines; D015363:Quinolones