Twisting and piezochromism of phenylene-ethynylenes with aromatic interactions between side chains and main chains

2014 ◽  
Vol 5 (11) ◽  
pp. 4184-4188 ◽  
Author(s):  
R. H. Pawle ◽  
T. E. Haas ◽  
P. Müller ◽  
S. W. Thomas III
Keyword(s):  
Solid State ◽  
Side Chains ◽  
Aromatic Interactions ◽  
Phenylene Ethynylenes

This paper describes a series of three-ring phenylene-ethynylenes (PEs) in which specific, non-covalent arene–arene interactions control conformation in the solid-state.

Cyclic hexapeptoids with N-alkyl side chains: solid-state assembly and thermal behaviour

CrystEngComm ◽  
2020 ◽  
Vol 22 (38) ◽  
pp. 6371-6384 ◽  
Author(s):  
Giovanni Pierri ◽  
Rosaria Schettini ◽  
Jürgen Nuss ◽  
Robert E. Dinnebier ◽  
Francesco De Riccardis ◽  
...  
Keyword(s):  
Solid State ◽  
Thermal Behaviour ◽  
Lattice Energy ◽  
Side Chains ◽  
X Ray Diffraction ◽  
Energy Calculations ◽  
X Ray ◽  
Alkyl Side Chains

The solid state assembly of two cyclic hexapeptoids decorated respectively with five and six carbon N-alkyl side chains is analyzed by X-ray diffraction, intermolecular energies and lattice energy calculations.

Solid State Structure and Photoluminescence properties of poly(2,5-dialkoxy-p-phenyleneethynylene)s

1995 ◽  
Vol 413 ◽  
Author(s):  
Christoph Weder ◽  
Michael J. Wagner ◽  
Mark S. Wrighton
Keyword(s):  
Solid State ◽  
Long Range ◽  
Photophysical Properties ◽  
Significant Degree ◽  
Range Order ◽  
Quantum Yields ◽  
Side Chains ◽  
Long Range Order ◽  
Rigid Rod ◽  
Covalently Linked

ABSTRACTIn an effort to better understand the relationship between molecular structure and photophysical properties, we have prepared and investigated a series of novel poly(2,5-dialkoxy-p-phenyleneethynylene)s. Wide angle X-ray diffraction measurements show that the supramolecular structure can be easily and significantly influenced by the nature of substituents covalently linked to the rigid-rod polymer main chains. Polymers which have sterically hindered side chains are essentially amorphous, while those with only linear side chains can form lamellar structures with a significant degree of long-range order. High photoluminescence quantum yields, up to 0.86 in solution and 0.36 in the solid state, have been measured. While the solution quantum yields are independent of the functionalization, solid state quantum efficiencies were found to be related to the degree of long-range order in the samples. In samples with a high degree of long-range order, the close proximity of the coplanar oriented polymer backbones is assumed to lead to the formation of eximer complexes which provide non emissive decay channels and, hence, result in comparable low photoluminescence quantum yields. In samples that adopt only a small extent of long-range order, the rigid-rod conjugated polymer backbones behave as if they were ‘dissolved’ in a hydrocarbon solvent and consequently high quantum efficiencies are obtained. Preliminary results indicate the suitability of these polymers as the emitting layer in electroluminescent devices.

scholarly journals Zinc-binding structure of a catalytic amyloid from solid-state NMR

2017 ◽  
Vol 114 (24) ◽  
pp. 6191-6196 ◽  
Author(s):  
Myungwoon Lee ◽  
Tuo Wang ◽  
Olga V. Makhlynets ◽  
Yibing Wu ◽  
Nicholas F. Polizzi ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Protein Misfolding ◽  
Molecular Size ◽  
Advanced Materials ◽  
Side Chains ◽  
Evolution Of Life ◽  
Water Activation ◽  
Catalytic Reactivity ◽  
Molecular Bases

Throughout biology, amyloids are key structures in both functional proteins and the end product of pathologic protein misfolding. Amyloids might also represent an early precursor in the evolution of life because of their small molecular size and their ability to self-purify and catalyze chemical reactions. They also provide attractive backbones for advanced materials. When β-strands of an amyloid are arranged parallel and in register, side chains from the same position of each chain align, facilitating metal chelation when the residues are good ligands such as histidine. High-resolution structures of metalloamyloids are needed to understand the molecular bases of metal–amyloid interactions. Here we combine solid-state NMR and structural bioinformatics to determine the structure of a zinc-bound metalloamyloid that catalyzes ester hydrolysis. The peptide forms amphiphilic parallel β-sheets that assemble into stacked bilayers with alternating hydrophobic and polar interfaces. The hydrophobic interface is stabilized by apolar side chains from adjacent sheets, whereas the hydrated polar interface houses the Zn2+-binding histidines with binding geometries unusual in proteins. Each Zn2+ has two bis-coordinated histidine ligands, which bridge adjacent strands to form an infinite metal–ligand chain along the fibril axis. A third histidine completes the protein ligand environment, leaving a free site on the Zn2+ for water activation. This structure defines a class of materials, which we call metal–peptide frameworks. The structure reveals a delicate interplay through which metal ions stabilize the amyloid structure, which in turn shapes the ligand geometry and catalytic reactivity of Zn2+.

Synthesis, crystallization, X-ray structural characterization and solid-state assembly of a cyclic hexapeptoid with propargyl and methoxyethyl side chains

2017 ◽  
Vol 73 (3) ◽  
pp. 399-412 ◽  
Author(s):  
Consiglia Tedesco ◽  
Eleonora Macedi ◽  
Alessandra Meli ◽  
Giovanni Pierri ◽  
Giorgio Della Sala ◽  
...  
Keyword(s):  
Solid State ◽  
Hydrogen Bonds ◽  
Structural Characterization ◽  
Crystal Form ◽  
Side Chains ◽  
Crystal Forms ◽  
Hydrate Crystal ◽  
The Stability ◽  
Efficient Packing

The synthesis and the structural characterization of a cyclic hexapeptoid with four methoxyethyl and two propargyl side chains have disclosed the presence of a hydrate crystal form [form (I)] and an anhydrous crystal form [form (II)]. The relative amounts of form (I) and form (II) in the as-purified product were determined by Rietveld refinement and depend on the purification procedures. In crystal form (I), peptoid molecules assemble in a columnar arrangement by means of side-chain-to-backbone C=CH...OC hydrogen bonds. In the anhydrous crystal form (II), cyclopeptoid molecules form ribbons by means of backbone-to-backbone CH2...OC hydrogen bonds, thus mimicking β-sheet secondary structures in proteins. In both crystal forms side chains act as joints among the columns or the ribbons and contribute to the stability of the whole solid-state assembly. Water molecules in the hydrate crystal form (I) bridge columns of cyclic peptoid molecules, providing a more efficient packing.

Interactions of protein side chains with RNA defined with REDOR solid state NMR

2011 ◽  
Vol 51 (3) ◽  
pp. 347-356 ◽  
Author(s):  
Wei Huang ◽  
Gabriele Varani ◽  
Gary P. Drobny
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Side Chains

The influence of oligo(ethylene glycol) side chains on the self-assembly of benzene-1,3,5-tricarboxamides in the solid state and in solution

2009 ◽  
Vol 19 (1) ◽  
pp. 124-130 ◽  
Author(s):  
Patrick J. M. Stals ◽  
Jan F. Haveman ◽  
Rafael Martín-Rapún ◽  
Carel F. C. Fitié ◽  
Anja R. A. Palmans ◽  
...  
Keyword(s):  
Solid State ◽  
Ethylene Glycol ◽  
Self Assembly ◽  
The Self ◽  
Side Chains

Polyesters with semifluorinated side chains: A proposal for the solid-state structure

2000 ◽  
Vol 38 (12) ◽  
pp. 1617-1625 ◽  
Author(s):  
Peter Friedel ◽  
Doris Pospiech ◽  
Dieter Jehnichen ◽  
J�rg Bergmann ◽  
Christopher K. Ober
Keyword(s):  
Solid State ◽  
Side Chains ◽  
State Structure ◽  
Solid State Structure
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