Synthetic Supercontainers Exhibit Distinct Solution versus Solid State Guest-Binding Behavior

2014 ◽  
Vol 136 (20) ◽  
pp. 7480-7491 ◽  
Author(s):  
Feng-Rong Dai ◽  
Uma Sambasivam ◽  
Alex J. Hammerstrom ◽  
Zhenqiang Wang
Keyword(s):  
Solid State ◽  
Solution Versus ◽  
Binding Behavior ◽  
Guest Binding ◽  
Distinct Solution

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.

Controlling the regioselectivity of the di-π-methane rearrangements of 1,2-naphtho-annelated barrelene derivatives — Solution versus solid-state photochemistry

2009 ◽  
Vol 87 (5) ◽  
pp. 619-626 ◽  
Author(s):  
Jia Luo ◽  
Heiko Ihmels ◽  
Hans-Jörg Deiseroth ◽  
Marc Schlosser
Keyword(s):  
Solid State ◽  
Transition State ◽  
Crystal Lattice ◽  
Reaction Medium ◽  
Product Distribution ◽  
Solution Versus ◽  
Selective Stabilization ◽  
Steric Constraints

The synthesis of 1,2-naphtho-annelated barrelene derivatives, namely dimethyl-7,12-dihydro-7,12-ethenobenzo[a]anthracene-13,14-dicarboxylate (4a) and dimethyl-7,14-dihydro-7,14-ethenodibenzo[a,j]-anthracene-15,16-dicarboxylate (4b), and the investigation of their photoreactivity in solution and in the solid state is reported. The irradiation of 4a and 4b resulted in regioselective di-π-methane rearrangements to give semibullvalene products; however, the product distribution is inverted upon changing the reaction medium from solution to the solid state. In solution, an α-naphtho–vinyl bridging predominates as the initial photochemical step because of the selective stabilization of the corresponding transition state, as discussed on the basis of the structures of the related biradical intermediates, whereas the solid-state photoreaction is significantly influenced by the steric constraints within the crystal lattice that only allow a β-naphtho–vinyl bridging.

Hydrogen bonding in a family of triamides: conformation-directing effects in solution versus the solid state

1990 ◽  
Vol 112 (23) ◽  
pp. 8630-8632 ◽  
Author(s):  
Gregory P. Dado ◽  
John M. Desper ◽  
Samuel H. Gellman
Keyword(s):  
Hydrogen Bonding ◽  
Solid State ◽  
Solution Versus

Spectrophotometric study of the selective binding behavior of aliphatic oligopeptides by bridged bis(β-cyclodextrin) linked by a 4,4′-diaminodiphenyl disulfide tether

2010 ◽  
Vol 88 (12) ◽  
pp. 1205-1212 ◽  
Author(s):  
Yang Yong-Cun ◽  
Chi Shao-Ming ◽  
Liu Ming-Hua ◽  
Huang Rong ◽  
Wang Yu-Fei ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Fluorescence Enhancement ◽  
Fluorescent Sensor ◽  
Binding Constants ◽  
2D Nmr ◽  
Binding Mode ◽  
Spectrophotometric Study ◽  
2D Nmr Spectroscopy ◽  
Binding Behavior ◽  
Guest Binding

The conformation and binding behavior of 4,4′-diaminodiphenyl disulfide bridged bis(β-cyclodextrin) (1) towards representative aliphatic oligopeptides, i.e., Leu-Gly, Gly-Leu, Glu-Glu, Met-Met, Gly-Gly, Gly-Gly-Gly, and Gly-Pro, were investigated by circular dichroism, fluorescence, and 1H and 2D NMR spectroscopy at 25 °C in phosphate buffer (pH 7.20). The results indicated that 1 acts as an efficient fluorescent sensor and displays remarkable fluorescence enhancement upon addition of optically inert oligopeptides. Owing to the cooperative host–linker–guest binding mode in which the linker and guest are coincluded in the two cyclodextrin cavities, the bis(β-cyclodextrin) 1 gives high binding constants of up to 103–104 (mol/L)–1 for oligopeptides. The bis(β-cyclodextrin) 1 can recognize not only the size and shape of oligopeptides but also the hydrophobicity, giving an exciting residue selectivity of up to 61.3 for the Gly-Leu/Glu-Glu pair. These phenomena are discussed from the viewpoints of multiple recognition and induce-fit interactions between host and guest.

Solution versus Solid-State Structure of Ytterbium Heterobimetallic Catalysts

2003 ◽  
Vol 125 (18) ◽  
pp. 5549-5558 ◽  
Author(s):  
Lorenzo Di Bari ◽  
Moreno Lelli ◽  
Guido Pintacuda ◽  
Gennaro Pescitelli ◽  
Fabio Marchetti ◽  
...  
Keyword(s):  
Solid State ◽  
State Structure ◽  
Solution Versus ◽  
Solid State Structure ◽  
Heterobimetallic Catalysts

Control of guest binding behavior of metal-containing host molecules by ligand exchange

2021 ◽  
Author(s):  
Shigehisa Akine
Keyword(s):  
Ligand Exchange ◽  
Exchange Reactions ◽  
Vast Number ◽  
Metal Centers ◽  
Binding Behavior ◽  
Host Molecules ◽  
Guest Binding

This review describes the control of guest binding behavior of metal-containing host molecules that is driven by ligand exchange reactions at the metal centers. Recently, a vast number of metal-containing...

scholarly journals A General Picture of Cucurbit[8]uril Host-Guest Binding: Recalibrating Bonded Interactions

2021 ◽  
Author(s):  
Zhaoxi Sun ◽  
Qiaole He ◽  
Zhihao Gong ◽  
Payam Kalhor ◽  
Zhe Huai ◽  
...  
Keyword(s):  
Force Fields ◽  
Drug Carriers ◽  
Theoretical Modelling ◽  
Binding Thermodynamics ◽  
Binding Behavior ◽  
Guest Binding ◽  
Recognition Motifs ◽  
Almost All ◽  
Amber Force Fields ◽  
Experimental Reference

Atomic-level understanding of the dynamical feature of host-guest interactions remains a central challenge in supramolecular chemistry. The remarkable guest binding behavior of the Cucurbiturils family of supramolecular containers makes them promising drug carriers. Among Cucurbit[n]urils, Cucurbit[8]uril (CB8) has intermediate portal size and cavity volume. It can exploit almost all host-guest recognition motifs formed by this host family. In our previous work, an extensive computational investigation of the binding of 7 commonly abused and structurally diverse drugs to the CB8 host was performed and a general dynamical binding picture of CB8-guest interactions was obtained. Further, two widely used fixed-charge models for drug-like molecules were investigated and compared in great detail, aiming at providing guidelines in choosing an appropriate charge scheme in host-guest modelling. Iterative refitting of atomic charges leads to improved binding thermodynamics and the best root-mean-squared deviation from the experimental reference is 2.6 kcal/mol. In this work, we focus on a thorough evaluation of the remaining parts of classical force fields, i.e., the bonded interactions. The widely used general Amber force fields are assessed and refitted to improve the intra-molecular conformational preference and thus the description of inter-molecular host-guest interactions. The interaction pattern and binding thermodynamics show significant dependence on the modelling parameters. The refitted system-specific parameter set improves the consistency of the modelling results and the experimental reference significantly. Finally, combining the previous charge-scheme comparison and the current force-field refitting, we provide general guidelines for the theoretical modelling of host-guest binding.

scholarly journals Synthesis and Guest-Binding Behavior of Water-Soluble Cyclophanes Bearing PEG Residues

2014 ◽  
Vol 04 (04) ◽  
pp. 409-416 ◽  
Author(s):  
Osamu Hayashida ◽  
Yuki Nakamura ◽  
Takuya Sato
Keyword(s):  
Water Soluble ◽  
Binding Behavior ◽  
Guest Binding
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