title: Vibrationally Resolved Absorption and Fluorescence Spectra of Firefly Luciferin: A Theoretical Simulation in the Gas Phase and in Solution.
abstract: Firefly bioluminescence has been applied in several fields. However, the absorption and fluorescence spectra of the substrate, luciferin, have not been observed at the vibrational level. In this study, the vibrationally resolved absorption and fluorescence spectra of firefly luciferin (neutral form LH2 , phenolate ion form LH(-) and dianion form L(2-) ) are simulated using the density functional method and convoluted by a Gaussian function, with displacement, distortion and Duschinsky effects in the framework of the Franck-Condon approximation. Both neutral and anionic forms of the luciferin are considered in the gas phase and in solution. The simulated spectra have desired band maxima with the experimental ones. The vibronic structure analysis reveals that the features of the most contributive vibrational modes coincide with the key geometry-changing region during transition between the ground state and the first singlet excited state.
authors.affiliation: Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China.
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Cheng
authors.affiliation: Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China.
authors.forename: Ya-Jun
authors.initials: YJ
authors.lastname: Liu
mesh_terms: D003198:Computer Simulation; D049454:Firefly Luciferin / Q000737:chemistry*; D005740:Gases; D008956:Models, Chemical; D015394:Molecular Structure; D011614:Psychotherapy, Brief; D013050:Spectrometry, Fluorescence; D013054:Spectrophotometry, Atomic
chemical_list: D005740:Gases; D049454:Firefly Luciferin