Self-Assembly of Perfluorodecanoic Acid with Cationic Copolymers:  Ultra-Low Energy Surfaces and Mesomorphous Structures

Langmuir ◽  
1998 ◽  
Vol 14 (17) ◽  
pp. 4898-4903 ◽  
Author(s):  
Andreas F. Thünemann ◽  
Kai Helmut Lochhaas
Keyword(s):  
Self Assembly ◽  
Low Energy ◽  
Perfluorodecanoic Acid ◽  
Cationic Copolymers ◽  
Energy Surfaces

Folding-Controlled Assembly of Ortho-Phenylene-Based Macrocycles

2020 ◽  
Author(s):  
Viraj kirinda ◽  
Scott Hartley
Keyword(s):  
Self Assembly ◽  
Structural Control ◽  
Structural Changes ◽  
Condensation Product ◽  
Gel Permeation Chromatography ◽  
Emergent Behavior ◽  
Order Structure ◽  
High Level ◽  
Alkoxy Groups ◽  
Energy Surfaces

The self-assembly of foldamers into macrocycles is a simple approach to non-biological higher-order structure. Previous work on the co-assembly of ortho-phenylene foldamers with rod-shaped linkers has shown that folding and self-assembly affect each other; that is, the combination leads to new emergent behavior, such as access to otherwise unfavorable folding states. To this point this relationship has been passive. Here, we demonstrate control of self-assembly by manipulating the foldamers’ conformational energy surfaces. A series of o-phenylene decamers and octamers have been assembled into macrocycles using imine condensation. Product distributions were analyzed by gel-permeation chromatography and molecular geometries extracted from a combination of NMR spectroscopy and computational chemistry. The assembly of o-phenylene decamers functionalized with alkoxy groups or hydrogens gives both [2+2] and [3+3] macrocycles. The mixture results from a subtle balance of entropic and enthalpic effects in these systems: the smaller [2+2] macrocycles are entropically favored but require the oligomer to misfold, whereas a perfectly folded decamer fits well within the larger [3+3] macrocycle that is entropically disfavored. Changing the substituents to fluoro groups, however, shifts assembly quantitatively to the [3+3] macrocycle products, even though the structural changes are well-removed from the functional groups directly participating in bond formation. The electron-withdrawing groups favor folding in these systems by strengthening arene–arene stacking interactions, increasing the enthalpic penalty to misfolding. The architectural changes are substantial even though the chemical perturbation is small: analogous o-phenylene octamers do not fit within macrocycles when perfectly folded, and quantitatively misfold to give small macrocycles regardless of substitution. Taken together, these results represent both a high level of structural control in structurally complex foldamer systems and the demonstration of large-amplitude structural changes as a consequence of a small structural effects.

Visualizing {110} Surface Structure of Equilibrium-form ZIF-8 Crystals by Low-dose Cs-corrected TEM

Nanoscale ◽  
2021 ◽  
Author(s):  
Xiaocang Han ◽  
Wenqian Chen ◽  
Rui Su ◽  
Yuan Tian ◽  
Pan Liu ◽  
...  
Keyword(s):  
Surface Structure ◽  
Low Dose ◽  
Low Energy ◽  
Zeolitic Imidazolate Frameworks ◽  
Equilibrium Form ◽  
Energy Surfaces

The properties of Zeolitic imidazolate frameworks (ZIFs) crystals highly depend on the structures of the low-energy surfaces, such as {110} of ZIF-8. However, the atomic/molecular configurations of the ZIF-8 {110}...

Self-assembly of germanium islands under pulsed irradiation by a low-energy ion beam during heteroepitaxy of Ge/Si(100) structures

2008 ◽  
Vol 106 (3) ◽  
pp. 517-527 ◽  
Author(s):  
J. V. Smagina ◽  
V. A. Zinovyev ◽  
A. V. Nenashev ◽  
A. V. Dvurechenskiĭ ◽  
V. A. Armbrister ◽  
...  
Keyword(s):  
Self Assembly ◽  
Ion Beam ◽  
Low Energy ◽  
Pulsed Irradiation

Two-level stochastic search of low-energy conformers for molecular spectroscopy: implementation and validation of MM and QM models

2019 ◽  
Vol 21 (36) ◽  
pp. 19921-19934 ◽  
Author(s):  
Balasubramanian Chandramouli ◽  
Sara Del Galdo ◽  
Marco Fusè ◽  
Vincenzo Barone ◽  
Giordano Mancini
Keyword(s):  
Potential Energy Surfaces ◽  
Molecular Spectroscopy ◽  
Stochastic Search ◽  
Low Energy ◽  
Stationary Points ◽  
Flexible Systems ◽  
Molecular Potential ◽  
Internal Motions ◽  
Molecular Potential Energy ◽  
Energy Surfaces

The search for stationary points in the molecular potential energy surfaces (PES) is a problem of increasing relevance in molecular sciences especially for large, flexible systems featuring several large-amplitude internal motions.

Experimental Approach for Developing and Testing Predictive Self-Assembly Models

2009 ◽  
Author(s):  
Gary Hendrick ◽  
James Tuckerman ◽  
Mario Juha ◽  
Nathan Crane
Keyword(s):  
Self Assembly ◽  
Binding Sites ◽  
Experimental Approach ◽  
Terminal Velocity ◽  
Low Energy ◽  
Assembly Process ◽  
Process Variables ◽  
Energy Limit ◽  
Testing Methods ◽  
Substrate Binding Sites

Testing methods and apparatus for studying capillary self-assembly processes are presented. This system permits the control of key self-assembly process variables so that relationships between process rates and yields and the process variables can be tested. Part arrival energies and angles are controlled by dropping through a fluid at terminal velocity onto fixed substrate binding sites. Using this system, the assembly probability at the low energy limit is shown to match a simple area fraction relationship.

Wetting of low-energy surfaces

2007 ◽  
Vol 134-135 ◽  
pp. 15-23 ◽  
Author(s):  
N.V. Churaev ◽  
V.D. Sobolev
Keyword(s):  
Low Energy ◽  
Energy Surfaces
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