title: The fluorescence properties of hypocrellin B and its amino-substituted derivative: photoinduced intramolecular proton transfer and photoinduced intramolecular electron transfer.
abstract: We report on the emission spectra and emission quantum yields of a newly synthesized hypocrellin dye, 2-demethoxy-2,3-ethylenediamino hypocrellin B (EDAHB), and its parent HB in different solvents of varying polarity. Our results demonstrate that EDAHB is one of the few dyes that exhibit highly solvent polarity-dependent fluorescence in the useful region (680-730 nm). Therefore, it offers some applications in the biomedical field as a fluorescent probe molecule. The solvatochromic effect of EDAHB is proposed to be due to a distinct change in the dipole moment of the dye on excitation. A photoinduced intramolecular proton transfer and a photoinduced intramolecular electron transfer process are considered relevant for the fluorescence properties of HB and EDAHB, respectively.
authors.affiliation: Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing, People's Republic of China. shangjie.xu@cup.uni-muenchen.de
authors.forename: Shangjie
authors.initials: S
authors.lastname: Xu
authors.forename: Xiaoxing
authors.initials: X
authors.lastname: Zhang
authors.forename: Shen
authors.initials: S
authors.lastname: Chen
authors.forename: Manhua
authors.initials: M
authors.lastname: Zhang
authors.forename: Tao
authors.initials: T
authors.lastname: Shen
mesh_terms: D004583:Electrons; D010569:Perylene / Q000031:analogs & derivatives* / Q000737:chemistry*; D017319:Photosensitizing Agents / Q000737:chemistry*; D011522:Protons; D011809:Quinones / Q000737:chemistry*; D011810:Quinoxalines / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: C581200:2-demethoxy-2,3-ethylenediamino hypocrellin B; D017319:Photosensitizing Agents; D011522:Protons; D011809:Quinones; D011810:Quinoxalines; D010569:Perylene; C064522:hypocrellin B