title: A new Hg(2+) -selective fluorescent sensor based on a 1,3-alternate thiacalix[4]arene anchored with four 8-quinolinoloxy groups.
abstract: A new thiacalix [4]arene derivative in a 1,3-alternate conformation bearing four quinolinoloxy groups through propyl chains has been synthesized, and its metal ion-binding and fluorescence-sensing properties were investigated in both THF and 10% H2O-THF systems. The designed ligand exhibited pronounced Hg2+ -selective on-off type fluoroionophoric properties among the representative transition and heavy metal ions including Cu2+. The detection limit for Hg2+ was found to be 2.0 x 10(-6) M in the mixed H2O-THF system. Detailed spectral studies including 1H NMR and MALDI-TOF mass spectroscopy reveal the unusual formation of a tetramercury complex with the ligand, in which the four propyl arms containing the quinolinoloxy groups adopt a "tetrapodand" conformation enclosing one Hg2+ ion each in the four cavities thus formed.
authors.affiliation: Chemical Sciences and Technology Division, National Institute for Interdisciplinary Science and Technology, NIST (Formerly Regional Research Laboratory), CSIR, Thiruvananthapuram, India.
authors.forename: L
authors.initials: L
authors.lastname: Praveen
authors.forename: V B
authors.initials: VB
authors.lastname: Ganga
authors.forename: R
authors.initials: R
authors.lastname: Thirumalai
authors.forename: T
authors.initials: T
authors.lastname: Sreeja
authors.forename: M L P
authors.initials: ML
authors.lastname: Reddy
authors.forename: R Luxmi
authors.initials: RL
authors.lastname: Varma
mesh_terms: D005456:Fluorescent Dyes / Q000737:chemistry*; D007477:Ions; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008628:Mercury / Q000737:chemistry*; D008670:Metals / Q000737:chemistry; D008956:Models, Chemical; D008968:Molecular Conformation; D010636:Phenols / Q000737:chemistry; D011485:Protein Binding; D013050:Spectrometry, Fluorescence; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013056:Spectrophotometry, Ultraviolet; D013440:Sulfides / Q000737:chemistry
chemical_list: D005456:Fluorescent Dyes; D007477:Ions; D008024:Ligands; D008670:Metals; D010636:Phenols; D013440:Sulfides; C500450:thiacalix(4)arene; D008628:Mercury