Molecular binding behavior of water-soluble calix[4]arenes with asymmetric 4,4′-bipyridinium guests in aqueous solution: regioselective recognition or not?

2016 ◽  
Vol 14 (46) ◽  
pp. 10804-10811 ◽  
Author(s):  
Kui Wang ◽  
Jian-Hua Cui ◽  
Si-Yang Xing ◽  
Hong-Xi Dou
Keyword(s):  
Aqueous Solution ◽  
Water Soluble ◽  
Molecular Binding ◽  
Binding Behavior

A unique regioselective recognition of N-methyl-N′-(naphthalen-2-ylmethyl)-4,4′-bipyridinium bromide iodide using a p-sulfonatocalix[4]arene was found.

Molecular binding behavior of bipyridium derivatives by water-soluble carboxylato-biphen[3]arene

2015 ◽  
Vol 51 (30) ◽  
pp. 6621-6624 ◽  
Author(s):  
Junwei Ma ◽  
Hongmei Deng ◽  
Suxiang Ma ◽  
Jian Li ◽  
Xueshun Jia ◽  
...  
Keyword(s):  
Water Soluble ◽  
Molecular Binding ◽  
Binding Behavior

Complexation of paraquat derivatives and bis(N-mono-substituted bipyridine) cations by a negatively charged carboxylato-biphen[3]arene in water is described.

High affinity of p-sulfonatothiacalix[4]arene with phenanthroline-diium in aqueous solution

RSC Advances ◽  
2015 ◽  
Vol 5 (4) ◽  
pp. 2640-2646 ◽  
Author(s):  
Kui Wang ◽  
En-Cui Yang ◽  
Xiao-Jun Zhao ◽  
Yu Liu
Keyword(s):  
Aqueous Solution ◽  
Molecular Binding ◽  
Binding Behavior ◽  
High Affinity ◽  
Order Of Magnitude ◽  
Sulfonated Calixarenes

The molecular binding behavior of sulfonated calixarenes with phenanthroline-diium guests were systemically investigated. p-Sulfonatothiacalix[4]arene shows a high affinity with phenanthroline-diium guests in the order of magnitude of 105 M−1.

Enantioselective Recognition of Chiral Guests by the Water-Soluble Chiral Keplerate {Mo132} Spherical Capsule with 30 Inner Lactate Ligands

2019 ◽  
Author(s):  
Nancy Watfa ◽  
Weimin Xuan ◽  
Zoe Sinclair ◽  
Robert Pow ◽  
Yousef Abul-Haija ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Chiral Recognition ◽  
Association Constants ◽  
Water Soluble ◽  
Enantioselective Recognition ◽  
H Nmr ◽  
Dosy Nmr ◽  
Spherical Capsule ◽  
Surface Pores ◽  
Guest Chemistry

Investigations of chiral host guest chemistry are important to explore recognition in confined environments. Here, by synthesizing water-soluble chiral porous nanocapsule based on the inorganic metal-oxo Keplerate-type cluster, {Mo<sub>132</sub>} with chiral lactate ligands with the composition [Mo<sub>132</sub>O<sub>372</sub>(H<sub>2</sub>O)<sub>72</sub>(<i>x-</i>Lactate)<sub>30</sub>]<sup>42-</sup> (<i>x</i> = D or L), it was possible to study the interaction with a chiral guest, L/D-carnitine and (<i>R</i>/<i>S</i>)-2-butanol in aqueous solution. The enantioselective recognition was studied by quantitative <sup>1</sup>H NMR and <sup>1</sup>H DOSY NMR which highlighted that the chiral recognition is regulated by two distinct sites. Differences in the association constants (K) of L- and D-carnitine, which, due to their charge, are generally restricted from entering the interior of the host, are observed, indicating that their recognition predominantly occurs at the surface pores of the structure. Conversely, a larger difference in association constants (K<i><sub>S</sub></i>/K<i><sub>R</sub></i> = 3) is observed for recognition within the capsule interior of (<i>R</i>)- and (<i>S</i>)-2-butanol.

scholarly journals Sulfobetaine Cryogels for Preferential Adsorption of Methyl Orange from Mixed Dye Solutions

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 208
Author(s):  
Ramona B. J. Ihlenburg ◽  
Anne-Catherine Lehnen ◽  
Joachim Koetz ◽  
Andreas Taubert
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Methyl Orange ◽  
Dye Removal ◽  
Selective Adsorption ◽  
Water Soluble ◽  
Organic Substances ◽  
Preferential Adsorption ◽  
Dimethyl Ammonium ◽  
Dye Solutions

New cryogels for selective dye removal from aqueous solution were prepared by free radical polymerization from the highly water-soluble crosslinker N,N,N’,N’-tetramethyl-N,N’-bis(2-ethylmethacrylate)-propyl-1,3-diammonium dibromide and the sulfobetaine monomer 2-(N-3-sulfopropyl-N,N-dimethyl ammonium)ethyl methacrylate. The resulting white and opaque cryogels have micrometer sized pores with a smaller substructure. They adsorb methyl orange (MO) but not methylene blue (MB) from aqueous solution. Mixtures of MO and MB can be separated through selective adsorption of the MO to the cryogels while the MB remains in solution. The resulting cryogels are thus candidates for the removal of hazardous organic substances, as exemplified by MO and MB, from water. Clearly, it is possible that the cryogels are also potentially interesting for removal of other compounds such as pharmaceuticals or pesticides, but this must be investigated further.

scholarly journals Synthesis and Guest-Binding Properties of pH/Reduction Dual-Responsive Cyclophane Dimer

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3097
Author(s):  
Osamu Hayashida ◽  
Yudai Tanaka ◽  
Takaaki Miyazaki
Keyword(s):  
Electrostatic Interaction ◽  
Disulfide Bonds ◽  
Water Soluble ◽  
Guest Molecules ◽  
Binding Behavior ◽  
Dual Responsive ◽  
Guest Binding ◽  
Basic Solutions ◽  
Ph Conditions ◽  
Almost All

A water-soluble cyclophane dimer having two disulfide groups as a reduction-responsive cleavable bond as well as several acidic and basic functional groups as a pH-responsive ionizable group 1 was successfully synthesized. It was found that 1 showed pH-dependent guest-binding behavior. That is, 1 strongly bound an anionic guest, 6-p-toluidinonaphthalene-2-sulfonate (TNS) with binding constant (K/M−1) for 1:1 host-guest complexes of 9.6 × 104 M−1 at pH 3.8, which was larger than those at pH 7.4 and 10.7 (6.0 × 104 and 2.4 × 104 M−1, respectively), indicating a favorable electrostatic interaction between anionic guest and net cationic 1. What is more, release of the entrapped guest molecules by 1 was easily controlled by pH stimulus. Large favorable enthalpies (ΔH) for formation of host-guest complexes were obtained under the pH conditions employed, suggesting that electrostatic interaction between anionic TNS and 1 was the most important driving force for host-guest complexation. Such contributions of ΔH for formation of host-guest complexes decreased along with increased pH values from acidic to basic solutions. Upon addition of dithiothreitol (DTT) as a reducing reagent to an aqueous PBS buffer (pH 7.4) containing 1 and TNS, the fluorescence intensity originating from the bound guest molecules decreased gradually. A treatment of 1 with DTT gave 2, having less guest-binding affinity by the cleavage of disulfide bonds of 1. Consequently, almost all entrapped guest molecules by 1 were released from the host. Moreover, such reduction-responsive cleavage of 1 and release of bound guest molecules was performed more rapidly in aqueous buffer at pH 10.7.

scholarly journals Blinking and nonradiant dark fraction of water-soluble quantum dots in aqueous solution

2005 ◽  
Vol 102 (40) ◽  
pp. 14284-14289 ◽  
Author(s):  
J. Yao ◽  
D. R. Larson ◽  
H. D. Vishwasrao ◽  
W. R. Zipfel ◽  
W. W. Webb
Keyword(s):  
Aqueous Solution ◽  
Quantum Dots ◽  
Water Soluble
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