title: Theoretical and experimental determination of the absorption and emission spectra of a prototypical indolenine-based squaraine dye.
abstract: The spectroscopy of a prototypical indolenine-based squaraine dye is analysed theoretically using state-of-the-art methodologies for the simulation of spectral lineshapes, and experimentally using optical absorption and emission spectroscopies. Density functional theory and its time-dependent extension are used to determine the stability of several conformers, to compute their excitation energies, equilibrium geometries and vibrational frequencies, both in the ground and in their first excited singlet state. Finally the generating function approach is used to simulate the vibronic lineshape of the low energy valence ππ* excitation and emission spectra. Solvent effects are also computed and discussed by using the polarizable continuum model. The developed model correctly reproduces the main spectral features of the squaraine, and allows us to identify the vibrational motions that mainly contribute to the observed lineshape.
authors.affiliation: Department of Agricultural, Forestry and Food Science, University of Torino, Via Leonardo da Vinci 44, I-10095 Grugliasco, Italy. raffaele.borrelli@unito.it.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Borrelli
authors.forename: Silvano
authors.initials: S
authors.lastname: Ellena
authors.forename: Claudia
authors.initials: C
authors.lastname: Barolo
mesh_terms: D004396:Coloring Agents / Q000737:chemistry*; D003503:Cyclobutanes / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D008958:Models, Molecular; D010636:Phenols / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013057:Spectrum Analysis
chemical_list: D004396:Coloring Agents; D003503:Cyclobutanes; D007211:Indoles; D010636:Phenols; C480596:squaraine