title: A self-organized ensemble of fluorescent 3-hydroxyflavone-Al (III) complex as sensor for fluoride and acetate ions.
abstract: Aluminum chloride addition results in a self-organized TURN-ON fluorescence of 3-hydroxyflavone (3HF) by a complexation reaction in MeOH and subsequent ligand exchange reaction with fluoride or acetate ions causes a fluorescence TURN-OFF of this complex, delivering a quantitative estimation route for fluoride and acetate ions. The ternary complex of 3HF with Al (III), a hard acid provides for a sensitive signalling system for fluoride ion, a hard base in the concentration range from 6 muM to 50 mM by a concerted co-ordination of fluoride ion involving an intermediate mechanistic pathway, while the complex is sensitive to acetate addition between 0-68 muM. The ligand exchange reaction of Al (3HF)(2) complex by fluoride or acetate ion, without interference from other common anions, has been investigated by UV-visible and fluorescence spetroscopies. The structure of the in-situ intermediate isolated at higher Al (3HF)(2) complex and acetate concentrations was inferred from the FT-IR spectrum and ESI-MS of the sample.
authors.affiliation: Department of Chemistry, Sri Sathya Sai Institute of Higher Learning, Prashanthi Nilayam, Anantapur, A.P-515134, India.
authors.forename: Sai
authors.initials: S
authors.lastname: Sathish
authors.forename: Govindh
authors.initials: G
authors.lastname: Narayan
authors.forename: Nageswara
authors.initials: N
authors.lastname: Rao
authors.forename: Chelli
authors.initials: C
authors.lastname: Janardhana
mesh_terms: D000085:Acetates / Q000737:chemistry*; D000535:Aluminum / Q000737:chemistry*; D047309:Flavones / Q000737:chemistry*; D005459:Fluorides / Q000737:chemistry*; D007477:Ions / Q000032:analysis; D008024:Ligands; D000432:Methanol / Q000737:chemistry; D015394:Molecular Structure; D013050:Spectrometry, Fluorescence
chemical_list: D000085:Acetates; D047309:Flavones; D007477:Ions; D008024:Ligands; D000535:Aluminum; D005459:Fluorides; D000432:Methanol