The self-assembling zwitterionic form ofL-phenylalanine at neutral pH

2014 ◽  
Vol 70 (3) ◽  
pp. 326-331 ◽  
Author(s):  
Estelle Mossou ◽  
Susana C. M. Teixeira ◽  
Edward P. Mitchell ◽  
Sax A. Mason ◽  
Lihi Adler-Abramovich ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Hydrogen Bonding ◽  
The Self ◽  
Monoclinic Space Group ◽  
X Rays ◽  
Asymmetric Unit ◽  
Zwitterionic Form ◽  
Self Assembling ◽  
Hydrogen Bonding Interactions ◽  
Resolution Structure

The title zwitterion (2S)-2-azaniumyl-1-hydroxy-3-phenylpropan-1-olate, C9H11NO2, also known as L-phenylalanine, was characterized using synchrotron X-rays. It crystallized in the monoclinic space groupP21with four molecules in the asymmetric unit. The 0.62 Å resolution structure is assumed to be closely related to the fibrillar form of phenylalanine, as observed by electron microscopy and electron diffraction. The structure exists in a zwitterionic form in which π–π stacking and hydrogen-bonding interactions are believed to form the basis of the self-assembling properties.

The Preparation and Crystal Structures of the 1 : 1 Adducts of 5-Nitrosalicylic Acid and 2-Chloro-3,5- dinitrobenzoic Acid with Triphenylphosphine Oxide

1998 ◽  
Vol 51 (5) ◽  
pp. 437 ◽  
Author(s):  
Graham Smith ◽  
Daniel E. Lynch ◽  
Colin H. L. Kennard ◽  
Karl A. Byriel
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Triphenylphosphine Oxide ◽  
Monoclinic Space Group ◽  
Intermolecular Hydrogen Bonding ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrogen Bonding Interactions ◽  
Phosphoryl Oxygen

The (1 : 1) adducts of 5-nitrosalicylic acid (5-nsa) and 2-chloro-3,5-dinitrobenzoic acid (cdnba) with triphenylphosphine oxide (tppo), [(5-nsa)(tppo)] (1) and [(cdnba)(tppo)] (2), have been prepared and their structures determined by X-ray diffraction and reffned to residuals R 0·045 (1) and 0·043 (2) for 2540 and 3265 observed reflections respectively. Crystals of both adducts are monoclinic, space group P21/c (1) and P21/a (2), with 4 dimer units in cells of dimensions a 16·217(1), b 7·6807(8), c 19·697(4) Å, β 113·357(8)° [for (1)] and a 16·009(5), b 8·687(1), c 17·640(5) Å, β 90·30(1)o [for (2)]. In both examples, the two molecules comprising the asymmetric unit are linked by a single hydrogen bond between the proton of the carboxylic acid and the phosphoryl oxygen of tppo [O- - -O, 2·524(3) Å (1); 2·72(3) Å (2)], while, in each case, the additional functional groups of the acid are not involved in any other intermolecular hydrogen-bonding interactions.

scholarly journals Crystal structure of 2-(methylamino)tropone

2019 ◽  
Vol 75 (8) ◽  
pp. 1128-1132
Author(s):  
Leandri Jansen van Vuuren ◽  
Hendrik G. Visser ◽  
Marietjie Schutte-Smith
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Monoclinic Space Group ◽  
Asymmetric Unit ◽  
Aromatic Rings ◽  
Small Deviations ◽  
Hydrogen Bonding Interactions ◽  
Complexes Of Transition Metals ◽  
Independent Molecules ◽  
The Stability

The title compound, 2-(methylamino)cyclohepta-2,4,6-trien-1-one, C8H9NO, crystallizes in the monoclinic space group P21/c, with three independent molecules in the asymmetric unit. The planarity of the molecules is indicated by planes fitted through the seven ring carbon atoms. Small deviations from the planes, with an extremal r.m.s. deviation of 0.0345 Å, are present. In complexes of transition metals with similar ligands, the large planar seven-membered aromatic rings have shown to improve the stability of the complex. Two types of hydrogen-bonding interactions, C—H...O and N—H...O, are observed, as well as bifurcation of these interactions. The N—H...O interactions link molecules to form infinite chains. The packing of molecules in the unit cell shows a pattern of overlapping aromatic rings, forming column-like formations. π–π interactions are observed between the overlapping aromatic rings at 3.4462 (19) Å from each other.

Directive Effect of Chain Length in Modulating Peptide Nano-assemblies

2020 ◽  
Vol 27 (9) ◽  
pp. 923-929
Author(s):  
Gaurav Pandey ◽  
Prem Prakash Das ◽  
Vibin Ramakrishnan
Keyword(s):  
Electron Microscopy ◽  
Amino Acids ◽  
Light Scattering ◽  
Chain Length ◽  
Self Assembly ◽  
The Self ◽  
Ionic Charge ◽  
Self Assembling ◽  
Biophysical Techniques

Background: RADA-4 (Ac-RADARADARADARADA-NH2) is the most extensively studied and marketed self-assembling peptide, forming hydrogel, used to create defined threedimensional microenvironments for cell culture applications. Objectives: In this work, we use various biophysical techniques to investigate the length dependency of RADA aggregation and assembly. Methods: We synthesized a series of RADA-N peptides, N ranging from 1 to 4, resulting in four peptides having 4, 8, 12, and 16 amino acids in their sequence. Through a combination of various biophysical methods including thioflavin T fluorescence assay, static right angle light scattering assay, Dynamic Light Scattering (DLS), electron microscopy, CD, and IR spectroscopy, we have examined the role of chain-length on the self-assembly of RADA peptide. Results: Our observations show that the aggregation of ionic, charge-complementary RADA motifcontaining peptides is length-dependent, with N less than 3 are not forming spontaneous selfassemblies. Conclusion: The six biophysical experiments discussed in this paper validate the significance of chain-length on the epitaxial growth of RADA peptide self-assembly.

Hydrophobic interaction and hydrogen bonding driving the self-assembling of quinoa protein and flavonoids

2021 ◽  
pp. 106807
Author(s):  
Kang Liu ◽  
Xue-Qiang Zha ◽  
Qiang-Ming Li ◽  
Li-Hua Pan ◽  
Jian-Ping Luo
Keyword(s):  
Hydrogen Bonding ◽  
Hydrophobic Interaction ◽  
The Self ◽  
Self Assembling

2,4,6-Trimethylpyridine-3,5-dicarbonitrile

2006 ◽  
Vol 62 (7) ◽  
pp. o2765-o2767
Author(s):  
Hong-Li Wang ◽  
Bin Zhang ◽  
Yi Dai
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Title Compound ◽  
Asymmetric Unit ◽  
Compound C ◽  
Hydrogen Bonding Interactions

The title compound, C10H9N3, is essently planar, except for the methyl H atoms. The asymmetric unit consists of two molecules. In the crystal structure, weak intramolecular C—H...N hydrogen-bonding interactions occur, linking the molecules into chains propagating along the a axis.

4,4′-Dibenzyl-5,5′-(pyridine-2,6-diyl)bis(3,4-dihydro-2H-1,2,4-triazole-3-thione)

2006 ◽  
Vol 62 (5) ◽  
pp. o1822-o1823
Author(s):  
Sibel Demir ◽  
Muharrem Dinçer ◽  
Ahmet Çetin ◽  
Osman Dayan ◽  
Ahmet Cansız
Keyword(s):  
Hydrogen Bonding ◽  
Title Compound ◽  
Tautomeric Form ◽  
Asymmetric Unit ◽  
Compound C ◽  
Hydrogen Bonding Interactions ◽  
Independent Molecules

The title compound, C23H19N7S2, adopts the ketoamine tautomeric form and displays C—H...N hydrogen-bonding interactions. There are two independent molecules in the asymmetric unit.

scholarly journals (η6-Benzene)(carbonato-κ2O,O′)[dicyclohexyl(naphthalen-1-ylmethyl)phosphane-κP]ruthenium(II) chloroform trisolvate

2014 ◽  
Vol 70 (7) ◽  
pp. m272-m273
Author(s):  
Saravanan Gowrisankar ◽  
Helfried Neumann ◽  
Anke Spannenberg ◽  
Matthias Beller
Keyword(s):  
Hydrogen Bonding ◽  
Metal Complex ◽  
Room Temperature ◽  
Crystal Packing ◽  
The Other ◽  
Asymmetric Unit ◽  
Carbonate Group ◽  
Acta Cryst ◽  
Hydrogen Bonding Interactions ◽  
Solvent Molecules

The title compound, [Ru(CO3)(η6-C6H6){(C6H11)2P(CH2C10H7)}]·3CHCl3, was synthesized by carbonation of [RuCl2(η6-C6H6){(C6H11)2P(CH2C10H7)}] with NaHCO3in methanol at room temperature. The RuIIatom is surrounded by a benzene ligand, a chelating carbonate group and a phosphane ligand in a piano-stool configuration. The crystal packing is consolidated by C—H...O and C—H...Cl hydrogen-bonding interactions between adjacent metal complexes and between the complexes and the solvent molecules. The asymmetric unit contains one metal complex and three chloroform solvent molecules of which only one was modelled. The estimated diffraction contributions of the other two strongly disordered chloroform solvent molecules were substracted from the observed diffraction data using the SQUEEZE procedure inPLATON[Spek (2009).Acta Cryst.D65, 148–155].

Poly[tetraamminecopper(II) bis[tris(μ2-cyanido-κ2C,N)dicuprate(I)]]: a unique CuI–CuIImixed-valence complex containing anionic cuprous cyanide layers and [Cu(NH3)4]2+cations

2012 ◽  
Vol 68 (2) ◽  
pp. m45-m47 ◽  
Author(s):  
Li-Na Jia ◽  
Lei Hou
Keyword(s):  
Hydrogen Bonding ◽  
Mixed Valence ◽  
Planar Geometry ◽  
Coordination Geometry ◽  
Asymmetric Unit ◽  
Hydrogen Bonding Interactions ◽  
Square Planar ◽  
Anionic Layer ◽  
Cuprous Cyanide ◽  
Cyanide Ligands

The title compound, {[Cu(NH3)4][Cu(CN)3]2}n, features a CuI–CuIImixed-valence CuCN framework based on {[Cu2(CN)3]−}nanionic layers and [Cu(NH3)4]2+cations. The asymmetric unit contains two different CuIions and one CuIIion which lies on a centre of inversion. Each CuIion is coordinated to three cyanide ligands with a distorted trigonal–planar geometry, while the CuIIion is ligated by four ammine ligands, with a distorted square-planar coordination geometry. The interlinkage between CuIions and cyanide bridges produces a honeycomb-like {[Cu2(CN)3]−}nanionic layer containing 18-membered planar [Cu(CN)]6metallocycles. A [Cu(NH3)4]2+cation fills each metallocyclic cavity within pairs of exactly superimposed {[Cu2(CN)3]−}nanionic layers, but there are no cations between the layers of adjacent pairs, which are offset. Pairs of N—H...N hydrogen-bonding interactions link the N—H groups of the ammine ligands to the N atoms of cyanide ligands.

Mastering nanostructured materials through H-bonding recognitions at interfaces

2010 ◽  
Vol 82 (4) ◽  
pp. 917-929 ◽  
Author(s):  
Stefan Mohnani ◽  
Anna Llanes-Pallas ◽  
Davide Bonifazi
Keyword(s):  
Hydrogen Bonding ◽  
Electronic Properties ◽  
Nanostructured Materials ◽  
Self Assembly ◽  
The Self ◽  
Memory Storage ◽  
Technological Application ◽  
Storage Devices ◽  
Hydrogen Bonding Interactions ◽  
Fundamental Research

The controlled engineering of functional architectures composed of π-systems with unusual opto-electronic properties is currently being investigated intensively from both fundamental research and technological application viewpoints. In particular, the exploitation of the supramolecular approach for the facile construction of multidimensional architectures, featuring cavities capable of hosting functional molecules, could be used in several applications, such as nanomedicine, molecular-based memory storage devices, and sensors. This paper highlights our recent strategies to use hydrogen-bonding interactions to prepare nanostructured functional architectures via the self-assembly of organic molecular modules studied at different interfaces.

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