title: Di- and Triphosphate Recognition and Sensing with Mono- and Dinuclear Fluorescent Zinc(II) Complexes: Clues for the Design of Selective Chemosensors for Anions in Aqueous Media.
abstract: The synthesis of a new ligand (L1) containing two 1,4,7-triazacyclononane ([9]aneN3) moieties linked by a 4,5-dimethylenacridine unit is reported. The binding and fluorescence sensing properties toward Cu2+, Zn2+, Cd2+, and Pb2+of L1 and receptor L2, composed of two [9]aneN3macrocycles bridged by a 6,6''-dimethylen-2,2':6',2''-terpyridine unit, have been studied by coupling potentiometric, UV/Vis absorption, and emission measurements in aqueous media. Both receptors can selectively detect Zn2+thanks to fluorescence emission enhancement upon metal binding. The analysis of the binding and sensing properties of the Zn2+complexes toward inorganic anions revealed that the dinuclear Zn2+complex of L1 selectively binds and senses the triphosphate anion (TP), whereas the mononuclear Zn2+complex of L2 displays selective recognition of diphosphate (DP). Binding of TP or DP induces emission quenching of the Zn2+complexes with L1 and L2, respectively. These results are exploited to discuss the role played by pH, number of coordinated metal cations, and binding ability of the bridging units in metal and/or anion coordination and sensing.
authors: Dipartimento di Chimica 'Ugo Schiff', Università degli Studi di Firenze, Via della Lastruccia 3, 50019, Sesto Fiorentino, Firenze, Italy.
authors: Francesco
authors: F
authors: Bartoli
authors: Dipartimento di Chimica 'Ugo Schiff', Università degli Studi di Firenze, Via della Lastruccia 3, 50019, Sesto Fiorentino, Firenze, Italy. andrea.bencini@unifi.it.
authors: Andrea
authors: http://orcid.org/0000-0003-3957-8451
authors: A
authors: Bencini
authors: Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Cagliari, S.S. 554 Bivio per Sestu, 09042, Monserrato, Italy.
authors: Alessandra
authors: A
authors: Garau
authors: Dipartimento di Chimica 'Ugo Schiff', Università degli Studi di Firenze, Via della Lastruccia 3, 50019, Sesto Fiorentino, Firenze, Italy.
authors: Claudia
authors: C
authors: Giorgi
authors: Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Cagliari, S.S. 554 Bivio per Sestu, 09042, Monserrato, Italy. lippolis@unica.it.
authors: Vito
authors: V
authors: Lippolis
authors: Dipartimento di Chimica 'Ugo Schiff', Università degli Studi di Firenze, Via della Lastruccia 3, 50019, Sesto Fiorentino, Firenze, Italy.
authors: Alessandro
authors: A
authors: Lunghi
authors: Dipartimento di Chimica 'Ugo Schiff', Università degli Studi di Firenze, Via della Lastruccia 3, 50019, Sesto Fiorentino, Firenze, Italy.
authors: Federico
authors: F
authors: Totti
authors: Dipartimento di Chimica 'Ugo Schiff', Università degli Studi di Firenze, Via della Lastruccia 3, 50019, Sesto Fiorentino, Firenze, Italy.
authors: Barbara
authors: B
authors: Valtancoli
keywords: anions; fluorescent complexes; phosphate binding; sensors; speciation