One- and two-dimensional polymers from proline and calcium bromide

2015 ◽  
Vol 71 (4) ◽  
pp. 311-317 ◽  
Author(s):  
Kevin Lamberts ◽  
Mihaela-Diana Şerb ◽  
Ulli Englert
Keyword(s):  
Aqueous Solution ◽  
Amino Acid ◽  
Coordination Sphere ◽  
Alkaline Earth ◽  
Two Dimensional ◽  
Counter Anion ◽  
Bridging Ligand ◽  
Dimensional Network ◽  
Earth Cation ◽  
Low Symmetry

Reactions of calcium bromide with enantiopure and racemic proline in aqueous solution lead to two solids in which the zwitterionic amino acid acts as a bridging ligand between neighbouring cations. Depending on the chirality of the amino acid, topologically very different products are obtained. With racemic proline, bromide acts as a simple uncoordinated counter-anion for the cationic heterochiral chains incatena-poly[[aquacalcium(II)]-μ-aqua-μ3-DL-proline-μ2-DL-proline], {[Ca(C5H9NO2)2(H2O)2]Br2}n. In agreement with chemical intuition, only carboxylate and aqua O atoms coordinate the alkaline earth cation in a low-symmetry arrangement. In contrast, L-proline affords the two-dimensional network poly[dibromidobis(μ2-L-proline)calcium(II)], [CaBr2(C5H9NO2)2]n, with an unexpected CaBr2unit in a more regular coordination sphere.

(R)-1-Phenylethanaminium–(S,S)-2,3-dibromosuccinate–(R,R)-2,3-dibromosuccinic acid–water (2/1/1/2)

2006 ◽  
Vol 62 (4) ◽  
pp. o1281-o1283
Author(s):  
Andreas Fischer
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Quantitative Yield ◽  
Acid Water ◽  
Two Dimensional ◽  
Rotation Axes ◽  
Compound C ◽  
Dimensional Network ◽  
Network Of Hydrogen Bonds

From an aqueous solution of racemic 2,3-dibromosuccinic acid and (R)-1-phenylethanamine, crystals of the title compound, C8H12N+·0.5C4H2Br2O4 2−·0.5C4H4Br2O4·H2O, were obtained in almost quantitative yield. The structure contains both enantiomers of the starting material, dibromosuccinic acid. The S,S enantiomer is present as a dianion and the R,R enantiomer as the neutral acid; both of these components lie on twofold rotation axes. The structure features a complex two-dimensional network of hydrogen bonds.

scholarly journals The tripeptideN-Cbz-βGly-Gly-Gly-Obz

2015 ◽  
Vol 71 (4) ◽  
pp. o240-o241
Author(s):  
Sumesh Nicholas
Keyword(s):  
Molecular Structure ◽  
Amino Acid ◽  
Benzyl Ester ◽  
Helical Conformation ◽  
Two Dimensional ◽  
Proteinogenic Amino Acid ◽  
Glycine Residue ◽  
The Third ◽  
Extended Conformation ◽  
Dimensional Network

The title peptide,N-benzyloxycarbonyl-β-glycylglycylglycine benzyl ester, C22H25N3O6, contains a non-proteinogenic amino acid residue, β-glycine, which is a homologated analogue of glycine. In the molecular structure, β-glycine adopts an extended conformation with atransconformation about its Cβ—Cαbond. The second glycine residue adopts an extended conformation while the third glycine residue adopts a helical conformation. In the crystal, three N—H...O hydrogen bonds, two involving the same carbonyl O atom as acceptor, results in an infinite two-dimensional network parallel to thebcplane.

A new two-dimensional anionic cadmium(II) polymer constructed through thiocyanate coordination bridges

2015 ◽  
Vol 71 (4) ◽  
pp. 318-321 ◽  
Author(s):  
Hui-Ting Wang ◽  
Xiao-Li Wang
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Hydrogen Bonds ◽  
Building Blocks ◽  
The Other ◽  
Supramolecular Network ◽  
Stacking Interactions ◽  
Two Dimensional ◽  
Thiocyanate Complex ◽  
Dimensional Network

A new cadmium–thiocyanate complex, poly[4-(dimethylamino)pyridin-1-ium [di-μ-thiocyanato-κ2N:S;κ2S:N-thiocyanato-κN-cadmium(II)]], {(C7H11N2)[Cd(NCS)3]}n, was synthesized by the reaction of cadmium thiocyanate and 4-(dimethylamino)pyridine hydrochloride in aqueous solution. In the crystal structure, each CdIIion is square-pyramidally coordinated by three N and two S atoms from five different thiocyanate ligands, four of which are bridging. The thiocyanate ligands play different roles in the build up of the structure; one role results in the formation of [Cd2(NCS)2] building blocks, while the other links the building blocks and cationsviaN—H...S hydrogen bonds. The N—H...S hydrogen bonds and weak π–π stacking interactions are involved in the formation of both a two-dimensional network structure and the supramolecular network.

Synthesis of Polynuclear Complexes with an Amino Acid or a Peptide as a Bridging Ligand

2008 ◽  
Vol 2 (2) ◽  
pp. 122-139
Author(s):  
Takashi Komiyama ◽  
Satoshi Igarashi ◽  
Yasuhiko Yukawa
Keyword(s):  
Amino Acid ◽  
Polynuclear Complexes ◽  
Bridging Ligand

Temperature Effect on the Two-Dimensional Phase Transition Kinetics of Adenine Adsorbed at the Hg Electrode/Aqueous Solution Interface

2003 ◽  
Vol 68 (8) ◽  
pp. 1407-1419 ◽  
Author(s):  
Claudio Fontanesi ◽  
Roberto Andreoli ◽  
Luca Benedetti ◽  
Roberto Giovanardi ◽  
Paolo Ferrarini
Keyword(s):  
Phase Transition ◽  
Aqueous Solution ◽  
Phase Change ◽  
Temperature Effect ◽  
Transition Rate ◽  
Effect Of Temperature ◽  
Two Dimensional ◽  
Solution Interface ◽  
Phase Transition Kinetics ◽  
Kinetics Of

The kinetics of the liquid-like → solid-like 2D phase transition of adenine adsorbed at the Hg/aqueous solution interface is studied. Attention is focused on the effect of temperature on the rate of phase change; an increase in temperature is found to cause a decrease of transition rate.

Über den Mechanismus der Bildung von Polyanionen in wäßriger Lösung. Zum Bildungsmechanismus eines Polytetramolybdations [Mo4O144-]n / On the Mechanism of Formation of Polyanions in Aqueous Solution. Concerning the Mechanism of Formation of a Polytetramolybdate Ion [Mo4O144-]n

1976 ◽  
Vol 31 (6) ◽  
pp. 737-748 ◽  
Author(s):  
Karl-Heinz Tytko
Keyword(s):  
Aqueous Solution ◽  
Coordination Sphere ◽  
Analytical Formula ◽  
Reaction Pathways ◽  
Mechanism Of Formation ◽  
X Ray ◽  
Theoretical Considerations

Possible structures and the pertinent reaction pathways for the polymetalate ion present in a slightly soluble polymetalate having the analytical formula A2O · 2 MOs have been derived on the basis of theoretical considerations. Structure and kind of combination of the tetrameric units of one of the possibilities are in agreement with the results of X-ray structure analyses. First the previously proposed planar tetrametalate ion [M4O12(OH)4]4--is formed by stepwise aggregation according to an addition mechanism. This species undergoes a rearrangement of the coordination sphere of two of the M atoms and is then subject to a polycondensation resulting in a polytetrametalate chain, [M4O144-]n.

Large-scale visualization of dispersion of liquid-exfoliated two-dimensional nanosheets

2021 ◽  
Author(s):  
Xingyu Cui ◽  
Wen ying Shi ◽  
Chao Lu
Keyword(s):  
Aqueous Solution ◽  
Large Scale ◽  
Fluorescence Microscope ◽  
Visualization Method ◽  
Two Dimensional ◽  
Non Invasive

An ultrafast, non-invasive and large-scale visualization method has been developed to evaluate the dispersion of two-dimensional nanosheets in aqueous solution with fluorescence microscope by formation of excimers from improvement of...

Aqueous solution thickening of amino acid‐based surfactant by alkylpyrrolidone

2021 ◽  
Author(s):  
Xuemin Liu ◽  
Ke Wu ◽  
Weili Song ◽  
Qiuyun Lei ◽  
Hui Zhang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Amino Acid
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