title: Synthesis and novel fluorescence phenomenon of terbium complex with a new Schiff base ligand derived from condensation of triaminotriethylamine and 3-indolemethanal.
abstract: A new Schiff base ligand with tripodal structure, N,N',N''-tri-(3-indolemethanal)-triaminotriethylamine (L), and its complex with terbium was synthesized. The complex was characterized by element analysis, IR spectra, mass spectra, thermal analysis and molar conductivity. The terbium ion was found to coordinate to the Schiff base nitrogen atoms and the bridgehead nitrogen atom. The fluorescence properties of the complex in aqueous solutions were studied. Under the excitation of UV light, the complex exhibits characteristic fluorescence of terbium ion. H(+) concentration could strongly enhance the luminescence of terbium complex with L in aqueous solutions. This phenomenon will make the new complex favorable to be used in the fluorescence switches and sensors. The mechanism of the fluorescence enhancement by protonation of the indole nitrogen atoms is due to the suppressed photoinduced electron transfer (PIET) fluorescence quenching when adding acid.
authors.affiliation: Key Lab of Energy Sources and Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan, Ningxia 750021, PR China. yang_tl@nxu.edu.cn
authors.forename: Tian-Lin
authors.initials: TL
authors.lastname: Yang
authors.forename: Wen-Wu
authors.initials: WW
authors.lastname: Qin
mesh_terms: D005029:Ethylenediamines / Q000737:chemistry; D005453:Fluorescence; D006358:Hot Temperature; D007211:Indoles / Q000737:chemistry; D008024:Ligands; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D012545:Schiff Bases / Q000737:chemistry; D013055:Spectrophotometry, Infrared; D013725:Terbium / Q000737:chemistry*
chemical_list: C522627:(N,N',N''-tris(3-indolemethanal)triaminotriethylamine)terbium(III); D005029:Ethylenediamines; D007211:Indoles; D008024:Ligands; D009942:Organometallic Compounds; D012545:Schiff Bases; D013725:Terbium; C099539:tris(2-aminoethyl)amine; C012381:indole-3-carbaldehyde