title: Characterization of 2-phenylbenzo[g]quinoxaline derivatives as viscosity-sensitive fluorescent probes.
abstract: To develop viscosity-sensitive fluorescent probes, five different substituted 2-phenylbenzo[g]quinoxaline derivatives (3a-e) were designed and synthesized by using benzo[g]quinoxaline as a fluorophore and phenyl ring bearing a rotatable single bond as a viscosity-sensitive unit. The fluorescence properties of these compounds were investigated in the media of the ethylene glycol-glycerol mixture with varied viscosity. It is found that 2-(4-hydroxyphenyl)benzo[g]quinoxaline (3d) and 2-(4-dimethylaminophenyl)-benzo[g]quinoxaline (3e) carrying stronger electron-donating groups in the phenyl ring show more sensitive fluorescence response to viscosity, revealing their potential use in viscosity detection and the key role of the substituted groups. The effects of solvent polarity and pH on the fluorescent properties of 3d and 3e were also discussed. The present study might be useful in developing viscosity-sensitive fluorescent probes.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Wang
authors.forename: Wen
authors.initials: W
authors.lastname: Shi
authors.forename: Jia
authors.initials: J
authors.lastname: Jia
authors.forename: Suming
authors.initials: S
authors.lastname: Chen
authors.forename: Huimin
authors.initials: H
authors.lastname: Ma
mesh_terms: D005453:Fluorescence; D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D011810:Quinoxalines / Q000138:chemical synthesis / Q000737:chemistry*; D012997:Solvents; D013329:Structure-Activity Relationship; D014783:Viscosity
chemical_list: D005456:Fluorescent Dyes; D011810:Quinoxalines; D012997:Solvents