Tritopic ion-pair receptors based on anion–π interactions for selective CaX2 binding

2018 ◽  
Vol 47 (24) ◽  
pp. 7883-7887 ◽  
Author(s):  
Jian Luo ◽  
Yu-Fei Ao ◽  
Christian Malm ◽  
Johannes Hunger ◽  
Qi-Qiang Wang ◽  
...  
Keyword(s):  
Binding Sites ◽  
Ion Pair ◽  
Π Interactions ◽  
Pentaethylene Glycol

Selective ion-pair binding of CaX2 (X = Br− and I−) was realized by a tritopic receptor incorporating two homoditopic anion–π binding sites and a pentaethylene glycol moiety.

scholarly journals Highly Efficient, Tripodal Ion-Pair Receptors for Switching Selectivity between Acetates and Sulfates Using Solid–Liquid and Liquid–Liquid Extractions

2020 ◽  
Vol 21 (24) ◽  
pp. 9465
Author(s):  
Marta Zaleskaya ◽  
Łukasz Dobrzycki ◽  
Jan Romański
Keyword(s):  
Binding Sites ◽  
Liquid Extraction ◽  
Ion Pair ◽  
Anion Binding ◽  
Binding Modes ◽  
Anion Receptor ◽  
X Ray ◽  
Liquid Liquid Extraction ◽  
Solid Liquid Extraction ◽  
Solid Liquid

A tripodal, squaramide-based ion-pair receptor 1 was synthesized in a modular fashion, and 1H NMR and UV-vis studies revealed its ability to interact more efficiently with anions with the assistance of cations. The reference tripodal anion receptor 2, lacking a crown ether unit, was found to lose the enhancement in anion binding induced by presence of cations. Besides the ability to bind anions in enhanced manner by the “single armed” ion-pair receptor 3, the lack of multiple and prearranged binding sites resulted in its much lower affinity towards anions than in the case of tripodal receptors. Unlike with receptors 2 or 3, the high affinity of 1 towards salts opens up the possibility of extracting extremely hydrophilic sulfate anions from aqueous to organic phase. The disparity in receptor 1 binding modes towards monovalent anions and divalent sulfates assures its selectivity towards sulfates over other lipophilic salts upon liquid–liquid extraction (LLE) and enables the Hofmeister bias to be overcome. By changing the extraction conditions from LLE to SLE (solid–liquid extraction), a switch of selectivity from sulfates to acetates was achieved. X-ray measurements support the ability of anion binding by cooperation of the arms of receptor 1 together with simultaneous binding of cations.

Bis[1-(4-bromobenzyl)-3-methylpyrazinium] bis(1,2-dicyanoethene-1,2-dithiolato-κ3 S,S′)nickelate(II)

2006 ◽  
Vol 62 (4) ◽  
pp. m767-m769
Author(s):  
Chun-Lin Ni ◽  
Ming-Guo Liu
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Ion Pair ◽  
Coordination Geometry ◽  
Π Interactions ◽  
Compound C ◽  
Square Planar

The title compound, (C12H12BrN2)[Ni(C4N2S2)2], is an ion-pair complex, isostructural with the Cl-containing analogue. The anion lies on an inversion centre and the NiII ion is coordinated by four S atoms, giving the expected square-planar coordination geometry. The cation adopts a conformation where the benzene and pyrazine rings are twisted with respect to the plane of the central C—C—N chain which links them. C—H...S and π–π interactions between cations and anions are observed in the crystal structure, and C—H...π interactions mediate the formation of ribbons of cations.

scholarly journals Ion Pair−π Interactions

2015 ◽  
Vol 137 (34) ◽  
pp. 11047-11056 ◽  
Author(s):  
Kaori Fujisawa ◽  
Marie Humbert-Droz ◽  
Romain Letrun ◽  
Eric Vauthey ◽  
Tomasz A. Wesolowski ◽  
...  
Keyword(s):  
Ion Pair ◽  
Π Interactions

Cation-Chloride Cotransport Mediated by An Ion Pair Transporter

2021 ◽  
Author(s):  
Jun Zhu ◽  
Xu-Dong Wang ◽  
Jian Luo ◽  
Yu-Fei Ao ◽  
Qi-Qiang Wang ◽  
...  
Keyword(s):  
Ion Transport ◽  
Binding Sites ◽  
Ion Pair ◽  
Anion Binding ◽  
Binding Property ◽  
H Nmr

Ion transport mediated by an ion pair receptor 1 bearing both cation and anion binding sites was presented. The ion pair binding property was revealed by means of 1H NMR...

Ion-Pair Recognition by Metal - Salophen and Metal - Salen Complexes

2012 ◽  
Vol 65 (12) ◽  
pp. 1638 ◽  
Author(s):  
Francesco Yafteh Mihan ◽  
Silvia Bartocci ◽  
Michele Bruschini ◽  
Paolo De Bernardin ◽  
Gianpiero Forte ◽  
...  
Keyword(s):  
Binding Sites ◽  
Ion Pairs ◽  
Anion Recognition ◽  
Short Review ◽  
Ion Pair ◽  
Cation Binding ◽  
Binding Motifs ◽  
Salen Complexes ◽  
Challenging Research ◽  
Anionic Species

The development of heteroditopic receptor systems that can simultaneously bind cationic and anionic species is one of the most challenging research topics in supramolecular chemistry, attracting the attention of a large number of research groups worldwide. Such an interest is due especially to the fact that the overall receptor–ion-pair complex is neutral and this can be advantageous in many situations, such as salt solubilization and extraction, and membrane-transport applications. Receptors designed for ion-pair complexation are molecules comprising well-known anion-binding motifs and familiar cation-binding sites. An important family of compounds that can use metal Lewis-acidic centres for anion recognition and that can be easily derivatized to introduce an additional binding site for the cation is metal–salophen and metal–salen complexes. This short review shows that the high versatility of salen and salophen ligands and of the corresponding metal complexes allows, through simple modifications of the basic skeleton, the obtention of highly efficient receptors for ion pairs.

Chloroquine-iron(III) tetra-arylporphyrin interactions and their effect on chloroquine oxidations catalyzed by iron(III) tetra-arylporphyrins

2005 ◽  
Vol 09 (05) ◽  
pp. 326-333 ◽  
Author(s):  
Ádamo César M. A. dos Santos ◽  
John R. Lindsay Smith ◽  
Marilda D. Assis
Keyword(s):  
Aqueous Solution ◽  
Complex Formation ◽  
Spectroscopic Study ◽  
Oxidation Product ◽  
Ion Pair ◽  
Oxidation Products ◽  
Methanolic Solution ◽  
Aqueous Buffer ◽  
Π Interactions ◽  
Π Complexation

This paper reports a UV-Vis spectroscopic study on the interactions of chloroquine with anionic, cationic and neutral tetra-arylporphyrins and their iron(III) complexes in aqueous buffer and in methanolic solution. This study reveals that in water at pH 6.4 cooperative ion-pair and π-π interactions lead to complex formation between the anionic porphyrin species and chloroquine. In methanolic solution no π-π complexation is observed. The neutral and cationic porphyrins and metalloporphyrins do not form complexes with chloroquine. On the basis of these results, the iron(III) porphyrins have been used as catalysts for the oxidation of chloroquine by iodosylbenzene. The main oxidation product in all systems is monodesethylchloroquine. The anionic iron(III) porphyrins are the most active catalysts; in aqueous solution they are selective for oxidative deethylation whereas in methanol they also give five other oxidation products. The cationic and neutral iron(III) porphyrins are poor or inactive catalysts for chloroquine oxidation by iodosylbenzene. The effect of iron(III) porphyrin/chloroquine interactions on the yields and selectivity of the oxidation is discussed.

scholarly journals Crystal structure and Hirshfeld surface analysis of 2-phenyl-1H-phenanthro[9,10-d]imidazol-3-ium benzoate

2020 ◽  
Vol 76 (5) ◽  
pp. 724-727
Author(s):  
Ruby Ahmed ◽  
Onur Erman Doğan ◽  
Farman Ali ◽  
Musheer Ahmad ◽  
Adeeba Ahmed ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Benzoic Acid ◽  
Surface Analysis ◽  
Ion Pair ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
Acid Form ◽  
Π Interactions ◽  
Compound C

In the title compound, C21H15N2 +·C7H5O2 −, 2-phenyl-1H-phenanthro[9,10-d]imidazole and benzoic acid form an ion pair complex. The system is consolidated by hydrogen bonds along with π–π interactions and N—H...π interactions between the constituent units. For a better understanding of the crystal structure and intermolecular interactions, a Hirshfeld surface analysis was performed.

Conformation of Ribosomes from Escherichia Coli

1974 ◽  
Vol 32 ◽  
pp. 210-211
Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Binding Sites ◽  
Ribosomal Proteins ◽  
Fluorescent Dyes ◽  
Protein Biosynthesis ◽  
Three Dimensional ◽  
Spatial Arrangement ◽  
Dimensional Structure ◽  
Complete Understanding ◽  
And Function

The present knowledge of the three-dimensional structure of ribosomes is far too limited to enable a complete understanding of the various roles which ribosomes play in protein biosynthesis. The spatial arrangement of proteins and ribonuclec acids in ribosomes can be analysed in many ways. Determination of binding sites for individual proteins on ribonuclec acid and locations of the mutual positions of proteins on the ribosome using labeling with fluorescent dyes, cross-linking reagents, neutron-diffraction or antibodies against ribosomal proteins seem to be most successful approaches. Structure and function of ribosomes can be correlated be depleting the complete ribosomes of some proteins to the functionally inactive core and by subsequent partial reconstitution in order to regain active ribosomal particles.

Electron Probe Analysis of Muscle

1982 ◽  
Vol 40 ◽  
pp. 398-401
Author(s):  
A. V. Somlyo ◽  
H. Shuman ◽  
A. P. Somlyo
Keyword(s):  
Skeletal Muscle ◽  
Smooth Muscle ◽  
Sarcoplasmic Reticulum ◽  
Resting State ◽  
Binding Sites ◽  
Electron Probe ◽  
Frog Skeletal Muscle ◽  
Electron Probe Analysis ◽  
Probe Analysis

Electron probe analysis of frozen dried cryosections of frog skeletal muscle, rabbit vascular smooth muscle and of isolated, hyperpermeab1 e rabbit cardiac myocytes has been used to determine the composition of the cytoplasm and organelles in the resting state as well as during contraction. The concentration of elements within the organelles reflects the permeabilities of the organelle membranes to the cytoplasmic ions as well as binding sites. The measurements of [Ca] in the sarcoplasmic reticulum (SR) and mitochondria at rest and during contraction, have direct bearing on their role as release and/or storage sites for Ca in situ.

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