Hybrid Macrocycles for Selective Binding and Sensing of Fluoride in Aqueous Solution

Synthesis and anion binding properties of hybrid macrocycles containing ammonium and hydrogen bond donor groups are reported. Receptor properties were studied in a 10 mM MES buffer solution at pH 6.2, at which the receptors carry two positive charges at the secondary amine groups. Receptor 1 was found to bind fluoride with the highest affinity (105 M-1) and selectivity among the synthesized receptors. It was the only receptor that demonstrated fluorescence increase upon addition of fluoride. Other titration experiments with halides and oxyanions led to an anion-induced aggregation and fluorescence quenching. The mechanism of the particular turn-on fluorescence for fluoride was explained by the ability of receptor 1 to encapsulate several fluoride anions. Multiple anion coordination resulted in the protonation of the tertiary amine group and subsequent hindering of the PET process. 1H and 19F NMR titrations, single-crystal X-ray structure of chloride complex, and DFT calculation suggest that 1 can perfectly accommodate two fluoride anions in the inner cavity but only one chloride, keeping the second chloride in the outer coordination sphere. Thus, the importance of size selectivity, which is reflected in a collective behavior of molecules in an aqueous solution, represents a new strategy for the design of highly selective probes for fluoride functioning in an aqueous solution. © 2018 American Chemical Society.

Oshchepkov A.S.1, 2 , Shumilova T.A.1 , Namashivaya S.R.1 , Fedorova O.A.2 , Dorovatovskii P.V.3 , Khrustalev V.N. 4 , Kataev E.A.1
Номер выпуска
  • 1 Institute of Chemistry, Faculty of Natural Sciences, Technische Universität Chemnitz, Chemnitz, 09107, Germany
  • 2 A. N. Nesmeyanov Institute of Organoelement Compounds of RAS, Vavilova Street, 28, Moscow, 119991, Russian Federation
  • 3 National Research Center Kurchatov Institute, 1 Acad. Kurchatov Sq., Moscow, 123182, Russian Federation
  • 4 Peoples' Friendship University of Russia, RUDN University, 6 Miklukho-Maklay Street, Moscow, 117198, Russian Federation
Ключевые слова
Binding energy; Bins; Chlorine compounds; Coordination reactions; Crystal structure; Design for testability; Fluorescence; Fluorescence quenching; Hydrogen bonds; Ions; Negative ions; Quenching; Single crystals; Solutions; Titration; Anion coordination; Chloride complexes; Collective behavior; Coordination sphere; Hydrogen bond donors; Selective binding; Single crystal x-ray structures; Tertiary amine groups; Fluorine compounds; ammonia; anion; fluoride; halide; macrocyclic compound; receptor; tertiary amine; aqueous solution; Article; chemical binding; crystal structure; density functional theory; fluorescence; fluorine nuclear magnetic resonance; molecular dynamics; proton nuclear magnetic resonance; proton transport; stereospecificity; synthesis
Дата создания
Дата изменения
Постоянная ссылка

Другие записи