title: Metal-Cation Recognition in Water by a Tetrapyrazinoporphyrazine-Based Tweezer Receptor.
abstract: A series of zinc azaphthalocyanines with two azacrowns in a rigid tweezer arrangement were prepared and the fluorescence sensing properties were investigated. The size-driven recognition of alkali and alkaline earth metal cations was significantly enhanced by the close cooperation of the two azacrown units, in which both donor nitrogen atoms need to be involved in analyte binding to switch the sensor on. The mono- or biphasic character of the binding isotherms, together with the binding stoichiometry and magnitude of association constants (KA ), indicated specific complexation of particular analytes. Water solvation was shown to play an important role and resulted in a strong quenching of sensor fluorescence in the ON state. The lead compound was embedded into silica nanoparticles and advantageous sensing properties towards K(+) were demonstrated in water (λF =671 nm, apparent KA =82 m(-1) , increase of 17×), even in the presence of (supra)physiological concentrations of Na(+) and Ca(2+) .
authors.affiliation: Department of Pharmaceutical Chemistry and Drug Control, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 50005, Hradec Kralove, Czech Republic.
authors.forename: Lukas
authors.initials: L
authors.lastname: Lochman
authors.affiliation: Department of Pharmaceutical Chemistry and Drug Control, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 50005, Hradec Kralove, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Svec
authors.affiliation: Department of Inorganic and Organic Chemistry, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 50005, Hradec Kralove, Czech Republic.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Roh
authors.affiliation: Institute of Inorganic Chemistry, v.v.i., Czech Academy of Sciences, Husinec-Řež 1001, 250 68, Řež, Czech Republic.
authors.forename: Kaplan
authors.initials: K
authors.lastname: Kirakci
authors.affiliation: Institute of Inorganic Chemistry, v.v.i., Czech Academy of Sciences, Husinec-Řež 1001, 250 68, Řež, Czech Republic.
authors.forename: Kamil
authors.initials: K
authors.lastname: Lang
authors.affiliation: Department of Pharmaceutical Chemistry and Drug Control, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 50005, Hradec Kralove, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Zimcik
authors.affiliation: Department of Biophysics and Physical Chemistry, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 50005, Hradec Kralove, Czech Republic. veronika.novakova@faf.cuni.cz.
authors.forename: Veronika
authors.identifier: http://orcid.org/0000-0002-2183-1220
authors.initials: V
authors.lastname: Novakova
keywords: cations; crown compounds; fluorescent probes; phthalocyanines; sensors