title: Zinc-specific fluorescent response of tris(isoquinolylmethyl)amines (isoTQAs).
abstract: Isoquinoline-based tetradentate ligands with C(3)-symmetry, tris(1- or 3-isoquinolylmethyl)amine (1- or 3-isoTQA), have been prepared and their zinc-induced fluorescence enhancement was investigated. Upon excitation at 324 nm, 1-isoTQA shows very weak fluorescence (ϕ = ∼0.003) in DMF/H(2)O (1/1) solution. In the presence of zinc ion, 1-isoTQA exhibits fluorescence increase (ϕ = 0.041) at 359 and 470 nm. This fluorescence enhancement at 470 nm is specific for zinc. However, 3-isoTQA exhibited a smaller fluorescence enhancement upon zinc complexation (ϕ = 0.017, λ(em) = 360 and 464 nm) compared with 1-isoTQA. Crystal structures of zinc complexes of isoTQAs demonstrate the diminished steric crowding and shorter Zn-N(aromatic) distances compared with isoTQENs (N,N,N',N'-tetrakis(isoquinolylmethyl)ethylenediamines) leads to a higher fluorescent response toward zinc relative to cadmium.
authors.affiliation: KYOUSEI Science Center, Faculty of Science, Nara Women's University, Nara 630-8506, Japan. mikata@cc.nara-wu.ac.jp
authors.forename: Yuji
authors.initials: Y
authors.lastname: Mikata
authors.forename: Keiko
authors.initials: K
authors.lastname: Kawata
authors.forename: Satoshi
authors.initials: S
authors.lastname: Iwatsuki
authors.forename: Hideo
authors.initials: H
authors.lastname: Konno
mesh_terms: D000588:Amines / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005453:Fluorescence; D008958:Models, Molecular; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D015032:Zinc / Q000737:chemistry*
chemical_list: D000588:Amines; D015032:Zinc