Switching Ion Binding Selectivity of Thiacalix[4]arene Monocrowns at Liquid–Liquid and 2D-Confined Interfaces

Understanding the interaction of ions with organic receptors in confined space is of fundamental importance and could advance nanoelectronics and sensor design. In this work, metal ion complexation of conformationally varied thiacalix[4]monocrowns bearing lower-rim hydroxy (type I), dodecyloxy (type II), or methoxy (type III) fragments was evaluated. At the liquid–liquid interface, alkylated thiacalixcrowns-5(6) selectively extract alkali metal ions according to the induced-fit concept, whereas crown-4 receptors were ineffective due to distortion of the crown-ether cavity, as predicted by quantum-chemical calculations. In type-I ligands, alkali-metal ion extraction by the solvent-accessible crown-ether cavity was prevented, which resulted in competitive Ag+ extraction by sulfide bridges. Surprisingly, amphiphilic type-I/II conjugates moderately extracted other metal ions, which was attributed to calixarene aggregation in salt aqueous phase and supported by dynamic light scattering measurements. Cation–monolayer interactions at the air–water interface were monitored by surface pressure/potential measurements and UV/visible reflection–absorption spectroscopy. Topology-varied selectivity was evidenced, towards Sr2+ (crown-4), K+ (crown-5), and Ag+ (crown-6) in type-I receptors and Na+ (crown-4), Ca2+ (crown-5), and Cs+ (crown-6) in type-II receptors. Nuclear magnetic resonance and electronic absorption spectroscopy revealed exocyclic coordination in type-I ligands and cation–π interactions in type-II ligands.

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Metal ion catalysis in nucleophilic displacement reactions at carbon, phosphorus, and sulfur centers. I. Catalysis by metal ions in the reaction of p-nitrophenyl diphenylphosphinate with ethoxide

Canadian Journal of Chemistry ◽

10.1139/v89-220 ◽

1989 ◽

Vol 67 (9) ◽

pp. 1440-1448 ◽

Cited By ~ 56

Author(s):

Edward J. Dunn ◽

Erwin Buncel

Keyword(s):

Crown Ether ◽

Alkali Metal ◽

Transition State ◽

Metal Ions ◽

Ground State ◽

Metal Ion ◽

Complexing Agents ◽

Transition State Stabilization ◽

Nucleophilic Displacement ◽

Metal Ion Catalysis

The effect of macrocyclic crown ether and cryptand complexing agents on the rate of the nucleophilic displacement reaction of p-nitrophenyl diphenylphosphinate by alkali metal ethoxides in ethanol at 25 °C has been studied by spectrophotometric techniques. For the reactions of potassium ethoxide, sodium ethoxide, and lithium ethoxide, the observed rate constant increased in the order KOEt < NaOEt < LiOEt. Crown ether and cryptand cation-complexing agents have a retarding effect on the rate. Increasing the ratio of complexing agent to base results in a decrease in kobs to a minimum value corresponding to the rate of reaction of free ethoxide ion. In complementary experiments, alkali metal ions were added to these reaction systems in the form of unreactive salts, causing an increase in reaction rate. The kinetic data were analysed in terms of ion-pairing treatments, which allowed evaluation of rate coefficients due to free ethoxide ions and metal ion – ethoxide ion pairs. Possible roles of the metal cations are discussed in terms of ground state and transition state stabilization. Evaluation of the equilibrium constants for association of the metal ion with ground state (Ka) and the transition state (K′a) shows that catalysis occurs as a result of enhanced association between the metal ion and the transition state, with (K′a) values increasing in the order K+ < Na+ < Li+. A model is proposed in which transition state stabilization arises largely from chelation of the solvated metal ion to two charged oxygen centers. This appears to be the first reported instance of catalysis by alkali metal cations in nucleophilic displacement at phosphoryl centers. Keywords: nucleophilic displacement at phosphorus, alkali-metal-ion catalysis.

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PEO-based electrolytes blended with star polymers with precisely imprinted polymeric pseudo-crown ether cavities for alkali metal ion batteries

Journal of Membrane Science ◽

10.1016/j.memsci.2019.01.051 ◽

2019 ◽

Vol 576 ◽

pp. 182-189 ◽

Cited By ~ 25

Author(s):

Zhuliu Xiao ◽

Binghua Zhou ◽

Jirong Wang ◽

Cai Zuo ◽

Dan He ◽

...

Keyword(s):

Crown Ether ◽

Alkali Metal ◽

Metal Ion ◽

Star Polymers ◽

Alkali Metal Ion

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Desorption of crown ether–alkali metal ion complexes in liquid secondary ion mass spectrometry (LSIMS)

Journal of the Chemical Society Perkin Transactions 2 ◽

10.1039/p29960000901 ◽

1996 ◽

pp. 901-905 ◽

Cited By ~ 3

Author(s):

Denis Giraud ◽

Isabelle Scherrens ◽

Marie-Laurence Lever ◽

Olivier Laprévote ◽

Bhupesh C. Das

Keyword(s):

Mass Spectrometry ◽

Crown Ether ◽

Alkali Metal ◽

Metal Ion ◽

Secondary Ion Mass Spectrometry ◽

Metal Ion Complexes ◽

Alkali Metal Ion ◽

Ion Mass Spectrometry ◽

Secondary Ion

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Membrane transport systems. II. Transport of alkali metal ions against their concentration gradients

Canadian Journal of Chemistry ◽

10.1139/v81-259 ◽

1981 ◽

Vol 59 (12) ◽

pp. 1734-1744 ◽

Cited By ~ 45

Author(s):

Thomas M. Fyles ◽

Virginia A. Malik-Diemer ◽

Dennis M. Whitfield

Keyword(s):

Alkali Metal ◽

Metal Ions ◽

Metal Ion ◽

Complex Function ◽

Membrane System ◽

Ion Concentration ◽

Transport Systems ◽

Alkali Metal Ions ◽

Concentration Gradients ◽

Membrane Transport Systems

An artificial membrane system based on a series of macrocyclic polyether carriers (crown ethers) is described. Under the influence of a proton gradient the carriers move alkali metal ions from basic to acidic solution through a chloroform membrane phase. Transport occurs against the concentration gradient of the transported ion as a result of a coupled counterflow of protons. Different transport behaviors are observed depending upon the metal ion concentration. At high metal ion concentration the amount transported is a linear function of time; at lower metal ion concentration the amount transported is a complex function of time which may be described as the result of a pair of consecutive first order processes. Effects of metal ion, carrier, and proton concentration on transport rate are considered. The rate increases with increasing metal ion or carrier concentration but is essentially independent of the pH of either aqueous phase. Increased lipophilicity of the carrier also results in a rate increase. Carriers derived from 18-crown-6 transport potassium selectively and all ions more rapidly than 15-crown-5 derivatives which are, however, selective for sodium. The overall efficiency of the system is discussed in terms of competing "leak" reactions, either of cations from the basic phase or of anions from the acidic phase.

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