The Host–Guest Properties Observed Between the Viologens and Cyclopentanocucurbit[6]uril

2020 ◽  
Vol 73 (7) ◽  
pp. 601
Author(s):  
Si-Yuan Cheng ◽  
Yun-Xia Qu ◽  
Zhu Tao ◽  
Kai-Zhi Zhou ◽  
Lian-Tong Wei ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Nmr Spectroscopy ◽  
Inclusion Complexes ◽  
Electronic Absorption ◽  
1H Nmr Spectroscopy ◽  
Guest Molecule ◽  
Binding Mode ◽  
Titration Calorimetry ◽  
Aryl Group ◽  
Guest Molecules

The interactions between cyclopentanocucurbit[6]uril (abbreviated as CyP6Q[6]) and a series of dialkyl-4,4′-bipyridinium and diaryl-4,4′-bipyridinium dicationic guest molecules, where the alkyl group is CH3(CH2)n with n=0–6 (expressed as G1 to G7) and the aryl group is phenylene (G8) and xylene (G9), have been investigated in aqueous solution using 1H NMR spectroscopy, isothermal titration calorimetry (ITC), and electronic absorption spectroscopy. Our results show that G1 and G2 form 1:1 host–guest inclusion complexes with CyP6Q[6], in which the bipyridinium core is partially embedded in the cavity of CyP6Q[6]. G3–G9 form 2:1 dumbbell-type host–guest inclusion complexes, in which the substituents are encapsulated by CyP6Q[6]. At the same time, CyP6Q[6] was compared with several other cucurbit[n]urils (Q[n]s) and their derivatives, such as Q[6], Q[7], and TMeQ[6], which have been reported to interact with this type of guest molecule. In its binding mode, CyP6Q[6] shows many interesting and different properties, and this difference was mainly reflected with G1 and G2.

scholarly journals A Study of the Interaction between Cucurbit[7]uril and Alkyl Substituted 4-Pyrrolidinopyridinium Salts

Chemistry ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 262-273 ◽  
Author(s):  
Weitao Xu ◽  
Xinyi Zhu ◽  
Bing Bian ◽  
Xin Xiao ◽  
Zhu Tao ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Aqueous Solution ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
Absorption Spectroscopy ◽  
Electronic Absorption ◽  
1H Nmr Spectroscopy ◽  
Electronic Absorption Spectroscopy ◽  
Pyridinium Nitrogen

The interaction between cucurbit[7]uril (Q[7]) and a series of 4-pyrrolidinopyridinium salts bearing aliphatic substituents at the pyridinium nitrogen, namely 4-(C4H8N)C5H5NRBr, where R = H (C0), Et (C2), n-butyl (C4), n-hexyl (C6), has been studied in aqueous solution by 1H NMR spectroscopy, electronic absorption spectroscopy, and mass spectrometry.

Investigation of the disorder of dibromo- and dichloromethane in their tri-ortho-thymotide clathrates using X-ray diffraction and solid-state 2H NMR spectroscopy

2011 ◽  
Vol 89 (7) ◽  
pp. 854-862
Author(s):  
Glenn A. Facey ◽  
Ilia Korobkov
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Guest Molecule ◽  
Type B ◽  
X Ray Diffraction ◽  
Guest Molecules ◽  
X Ray ◽  
Twofold Axis ◽  
H Nmr ◽  
Heavy Atoms

The tri-ortho-thymotide (TOT) clathrates of dibromo- and dichloromethane were characterized by single crystal X-ray diffraction at 200 K and solid-state 2H NMR spectroscopy as a function of temperature. The host structure was found to be typical of other cage-type TOT clathrates. The X-ray results showed a substantial amount of disorder among the guest molecules. In both clathrates, multiple guest molecule positions could be modeled. The heavy atoms of all the guest molecule positions lie approximately in the same plane, with some out-of-plane distortion. The guest molecules were of two different types in positions symmetric about the crystallographic twofold rotation axis: type A guests, with carbon atoms well removed from the crystallographic twofold axis, and type B guests, with carbon atoms very close to the twofold axis. The 2H NMR spectra for the guests confirmed that the disorder was dynamic. The experimental results could be accounted for by the presence of three simultaneous types of molecular motion, all fast with respect to the 2H quadrupolar interaction: (i) twofold molecular flips about the molecular C2 symmetry axis, (ii) exchange between the type A and type B sites in a single plane, and (iii) a two-site libration of the plane containing the heavy atoms of the A and B guest sites with a temperature-dependent amplitude.

Comparative conformational analyses of μ-selective dermorphin and §-selective deltorphin-II in aqueous solution by 1H-NMR spectroscopy

2009 ◽  
Vol 44 (3) ◽  
pp. 295-304 ◽  
Author(s):  
MOTOZUMU SEGAWA ◽  
YASUNORI OHNO ◽  
MITSUNOBU DOI ◽  
MASATOSHI INOUE ◽  
TOSHIMASA ISHIDA ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Deltorphin Ii

Supramolecular Chemistry of Pyronines B and Y, β-Cyclodextrin and Linked β-Cyclodextrin Dimers

2010 ◽  
Vol 63 (4) ◽  
pp. 687 ◽  
Author(s):  
Huy T. Ngo ◽  
Philip Clements ◽  
Christopher J. Easton ◽  
Duc-Truc Pham ◽  
Stephen F. Lincoln
Keyword(s):  
Aqueous Solution ◽  
Nmr Spectroscopy ◽  
Fluorescence Quenching ◽  
Supramolecular Chemistry ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Complexation Constants

The complexation of cationic pyronine B (PB+) and pyronine Y (PY+) by β-cyclodextrin (βCD) and two linked βCD dimers, N,N′-bis((2AS,3AS)-3A-deoxy-β-cyclodextrin-3A-yl)succinamide, 33βCD2suc, and N,N′-bis(6A-deoxy-β-cyclodextrin-6A-yl)succinamide, 66βCD2suc, in aqueous solution has been studied by UV-vis, fluorescence, and 1H NMR spectroscopy. The complexation constants for the 1:1 complexes: βCD.PB+, 33βCD2suc.PB+, 66βCD2suc.PB+, and the analogous PY+ complexes are reported as are the dimerization constants for PB+ and PY+. The modes of complexation, dimerization, and fluorescence quenching are discussed.

scholarly journals Study of the host–guest interaction between N,N′-bis[4-(dimethylaminophenyl)methyl]butane-1,4-diamine and the cucuribit[n]urils (n = 6, 7)

2019 ◽  
Vol 43 (37) ◽  
pp. 14938-14943 ◽  
Author(s):  
Zhiyou Xiao ◽  
Yang Zhou ◽  
Weitao Xu ◽  
Timothy J. Prior ◽  
Bing Bian ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Isothermal Titration Calorimetry ◽  
Absorption Spectroscopy ◽  
Electronic Absorption ◽  
Electronic Absorption Spectroscopy ◽  
Titration Calorimetry ◽  
H Nmr

Interaction of the cucuribit[n]urils (n = 6 or 7) and the guest N,N′-bis[4-(dimethylaminophenyl)methyl]butane-1,4-diamine (G) has been studied in aqueous solution by 1H NMR and electronic absorption spectroscopy and Isothermal Titration Calorimetry.

Encapsulation of L-Valine, D-Leucine and D-Methionine by Cucurbit[8]uril

CrystEngComm ◽  
2022 ◽  
Author(s):  
Zenghui Zhang ◽  
Rui-Lian Lin ◽  
Xiangyun Yu ◽  
Li-Xia Chen ◽  
Zhu Tao ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Solid State ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Binding Interactions ◽  
X Ray ◽  
X Ray Crystallography

The binding interactions of cucurbit[8]uril (Q[8]) with L-Valine, D-Leucine, and D-Methionine, both in aqueous solution and solid state, have been studied by 1H NMR spectroscopy and X-ray crystallography. 1H NMR...

Energetics of the encapsulation of o-, m-, and p-hydroxybenzoic acids by β-cyclodextrin and its methylated and hydroxypropylated derivatives in aqueous solution

1999 ◽  
Vol 77 (3) ◽  
pp. 348-355 ◽  
Author(s):  
Elena Junquera ◽  
Valentin G Baonza ◽  
Emilio Aicart
Keyword(s):  
Aqueous Solution ◽  
Inclusion Complex ◽  
Aqueous Solutions ◽  
Inclusion Complexes ◽  
Binding Constant ◽  
Substituent Effect ◽  
Binding Constants ◽  
Hydroxybenzoic Acid ◽  
Guest Molecules ◽  
Hydroxybenzoic Acids

A fully computerized potentiometric technique has been used to analyze the energetics of the encapsulation of o-, m-, and p-hydroxybenzoic acids by β-cyclodextrin (β-CD) and (or) two of its most used derivatives: 2,6-di-O-methyl-β-cyclodextrin (DIMEB) and hydroxypropyl-β-cyclodextrin (HPBCD). The study has been carried out by measuring the pH of aqueous solutions of the three hydroxyacids in the absence of cyclodextrin at 25°C, and in the presence of cyclodextrin at several temperatures ranging from 15 to 40°C, keeping constant the concentration of the guest. The dissociation constant of the acids and the binding constants of the inclusion complexes formed have been simultaneously determined at all the temperatures by using a model previously derived by us. The carboxylic forms have been found to bind the CD with higher affinities than the carboxylate partners do, irrespective of the temperature, the cyclodextrin used, and the position of the substituents on the guest molecules. The formation of the inclusion complexes studied in this work has been found to be enthalpy driven, with a favorable enthalpic term dominant over an unfavorable entropic one. The effect of the substituents of both guest and host molecules on the thermodynamics of the inclusion processes has been analyzed. Key words: binding constant, β-cyclodextrin, hydroxybenzoic acid, inclusion complex, substituent effect.

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