title: Fluorescent anion sensor derived from cholic acid: the use of flexible side chain.
abstract: [structure: see text] The fluorescent photoinduced electron transfer (PET) chemosensors 1-3 were synthesized from cholic acid. 1 and 2 containing amidothiourea groups as anion receptive sites demonstrated much higher affinity toward anions than 3 containing traditional thiourea H-bond donating group. Comparative studies on their binding affinity toward carboxylates, dihydrogen phosphate, and halides revealed that the amidothiourea moiety on the C17 side chain could work cooperatively with H-bond donating groups on C7 and C12 to bind spherical halogen anions. An unexpected specific fluorescence enhancement of 1 by coordinating bromide ion was observed.
authors.affiliation: Department of Chemistry and Central Laboratory of the Institute of Molecular Technology for Drug Discovery and Synthesis, Hong Kong Baptist University, Hong Kong SAR, PR China.
authors.forename: Lei
authors.initials: L
authors.lastname: Fang
authors.forename: Wing-Hong
authors.initials: WH
authors.lastname: Chan
authors.forename: Yong-Bing
authors.initials: YB
authors.lastname: He
authors.forename: Daniel W J
authors.initials: DW
authors.lastname: Kwong
authors.forename: Albert W M
authors.initials: AW
authors.lastname: Lee
mesh_terms: D000838:Anions / Q000032:analysis*; D015374:Biosensing Techniques / Q000379:methods*; D002793:Cholic Acids / Q000138:chemical synthesis*; D005453:Fluorescence; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy
chemical_list: D000838:Anions; D002793:Cholic Acids