π-Electron Systems That Form Planar and Interlocked Anion Complexes and Their Ion-Pairing Assemblies

2015 ◽  
Vol 22 (2) ◽  
pp. 626-638 ◽  
Author(s):  
Ryohei Yamakado ◽  
Tsuneaki Sakurai ◽  
Wakana Matsuda ◽  
Shu Seki ◽  
Nobuhiro Yasuda ◽  
...  
Keyword(s):  
Ion Pairing ◽  
Electron Systems ◽  
Anion Complexes

Ion-Pairing Crystal Polymorphs of Interlocked [2 + 1]-Type Receptor–Anion Complexes

2016 ◽  
Vol 81 (18) ◽  
pp. 8530-8536 ◽  
Author(s):  
Ryohei Yamakado ◽  
Ryuma Sato ◽  
Yasuteru Shigeta ◽  
Hiromitsu Maeda
Keyword(s):  
Ion Pairing ◽  
Anion Complexes ◽  
Type Receptor

Ion‐Pairing Assemblies of Porphyrin–Au III Complexes in Combination with π‐Electronic Receptor–Anion Complexes

2020 ◽  
Vol 15 (4) ◽  
pp. 494-498 ◽  
Author(s):  
Hiroki Tanaka ◽  
Yohei Haketa ◽  
Yuya Bando ◽  
Ryohei Yamakado ◽  
Nobuhiro Yasuda ◽  
...  
Keyword(s):  
Ion Pairing ◽  
Anion Complexes

Dimension-controlled ion-pairing assemblies based on π-electronic charged species

2017 ◽  
Vol 53 (20) ◽  
pp. 2894-2909 ◽  
Author(s):  
Yohei Haketa ◽  
Hiromitsu Maeda
Keyword(s):  
Recent Progress ◽  
Ion Pairs ◽  
Ion Pairing ◽  
Feature Article ◽  
Charged Species ◽  
Anion Complexes

This feature article summarizes the recent progress in the study of ion-pairing assemblies based on π-electronic ion pairs, including anion complexes of π-electronic molecules.

Photo-responsive dimension-controlled ion-pairing assemblies based on anion complexes of π-electronic systems

2019 ◽  
Vol 55 (69) ◽  
pp. 10269-10272 ◽  
Author(s):  
Ryohei Yamakado ◽  
Yohei Haketa ◽  
Mitsuo Hara ◽  
Shusaku Nagano ◽  
Takahiro Seki ◽  
...  
Keyword(s):  
Ion Pairing ◽  
Electronic Systems ◽  
Aliphatic Chain ◽  
Anion Complexes

Negatively charged π-electronic systems, prepared by the complexation of dipyrrolyldiketone BF2 complexes with an azobenzene bearing an alkanoate and an aliphatic chain, provided dimension-controlled assemblies, showing the photo-responsive behaviour.

Ion-Pairing Assemblies Comprising Anion Complexes of π-Extended Anion-Responsive Molecules

2019 ◽  
Vol 84 (14) ◽  
pp. 8886-8898 ◽  
Author(s):  
Shinya Sugiura ◽  
Wakana Matsuda ◽  
Wanying Zhang ◽  
Shu Seki ◽  
Nobuhiro Yasuda ◽  
...  
Keyword(s):  
Ion Pairing ◽  
Anion Complexes

Ion Pairing and Dielectric Decrement in Glycosaminoglycan Brushes

2020 ◽  
Author(s):  
James Sterling ◽  
Wenjuan Jiang ◽  
Wesley M. Botello-Smith ◽  
Yun L. Luo
Keyword(s):  
Molecular Dynamics ◽  
Ion Pairs ◽  
Mean Field ◽  
Salt Bridge ◽  
Ion Pairing ◽  
Donnan Potential ◽  
Mean Field Models ◽  
Ion Exclusion ◽  
Dynamics Simulations ◽  
Contact Ion Pairs

Molecular dynamics simulations of hyaluronic acid and heparin brushes are presented that show important effects of ion-pairing, water dielectric decrease, and co-ion exclusion. Results show equilibria with electroneutrality attained through screening and pairing of brush anionic charges by cations. Most surprising is the reversal of the Donnan potential that would be expected based on electrostatic Boltzmann partitioning alone. Water dielectric decrement within the brush domain is also associated with Born hydration-driven cation exclusion from the brush. We observe that the primary partition energy attracting cations to attain brush electroneutrality is the ion-pairing or salt-bridge energy associated with cation-sulfate and cation-carboxylate solvent-separated and contact ion pairs. Potassium and sodium pairing to glycosaminoglycan carboxylates and sulfates consistently show similar abundance of contact-pairing and solvent-separated pairing. In these crowded macromolecular brushes, ion-pairing, Born-hydration, and electrostatic potential energies all contribute to attain electroneutrality and should therefore contribute in mean-field models to accurately represent brush electrostatics.

Pathway Complexity in the Stacking of Imine-linked Macrocycles Related to Two-Dimensional Covalent Organic Frameworks

2019 ◽  
Author(s):  
Shiwei Wang ◽  
Anton Chavez ◽  
Simil Thomas ◽  
Hong Li ◽  
Nathan C. Flanders ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Structural Similarity ◽  
Discrete Models ◽  
Side Chains ◽  
Two Dimensional ◽  
Assembly Process ◽  
Covalent Organic Frameworks ◽  
Electron Systems ◽  
Monomer Structure ◽  
Kinetic Traps

This work reports on the assembly of imine-linked macrocycles that serve as models of two-dimensional covalent organic frameworks (2D COFs). Interlayer interactions play an important role in the formation of 2D COFs, yet the effect of monomer structure on COF formation, crystallinity, and susceptibility to exfoliation are not well understood. For example, monomers with both electron-rich and electron-poor π-electron systems have been proposed to strengthen interlayer inter-actions and improve crystallinity. Here we probe these effects by studying the stacking behavior of imine-linked macrocycles that represent discrete models of 2D COFs. <div><br></div><div>Specifically, macrocycles based on terephthaldehyde (PDA) or 2,5-dimethoxyterephthaldehyde (DMPDA) stack upon cooling molecularly dissolved solutions. Both macrocycles assemble cooperatively with similar ΔHe values of -97 kJ/mol and -101 kJ/mol, respectively, although the DMPDA macrocycle assembly process showed a more straightforward temperature dependence. Circular dichroism spectroscopy performed on macrocycles bearing chiral side chains revealed a helix reversion process for the PDA macrocycles that was not observed for the DMPDA macrocycles. <br></div><div><br></div><div>Given the structural similarity of these monomers, these findings demonstrate that the stacking processes associated with nanotubes derived from these macrocycles, as well as for the corresponding COFs, are complex and susceptible to kinetic traps, casting doubt on the relevance of thermodynamic arguments for improving materials quality. <br></div>

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