scholarly journals Controlling orthogonal self-assembly through cis–trans isomerization of a non-covalent palladium complex dimer

2018 ◽  
Vol 54 (17) ◽  
pp. 2094-2097 ◽  
Author(s):  
Zoran Kokan ◽  
Borislav Kovačević ◽  
Zoran Štefanić ◽  
Pavleta Tzvetkova ◽  
Srećko I. Kirin

Self-assembly of a chiral complex dimer held by 16 hydrogen bonds was controlled through configurational isomerization of the metal center.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jichuan Zhang ◽  
Yongan Feng ◽  
Richard J. Staples ◽  
Jiaheng Zhang ◽  
Jean’ne M. Shreeve

AbstractOwing to its simple preparation and high oxygen content, nitroformate [−C(NO2)3, NF] is an extremely attractive oxidant component for propellants and explosives. However, the poor thermostability of NF-based derivatives has been an unconquerable barrier for more than 150 years, thus hindering its application. In this study, the first example of a nitrogen-rich hydrogen-bonded organic framework (HOF-NF) is designed and constructed through self-assembly in energetic materials, in which NF anions are trapped in pores of the resulting framework via the dual force of ionic and hydrogen bonds from the strengthened framework. These factors lead to the decomposition temperature of the resulting HOF-NF moiety being 200 °C, which exceeds the challenge of thermal stability over 180 °C for the first time among NF-based compounds. A large number of NF-based compounds with high stabilities and excellent properties can be designed and synthesized on the basis of this work.


2016 ◽  
Vol 43 (12) ◽  
pp. 1732-1738 ◽  
Author(s):  
Feifei Wang ◽  
Ping Song ◽  
Huai Yang ◽  
Xibin Shao

2014 ◽  
Vol 70 (a1) ◽  
pp. C1474-C1474
Author(s):  
Patrice Kenfack ◽  
Emmanuel Wenger ◽  
Slimane Dahaoui ◽  
John Lambi ◽  
Pierrick Durand ◽  
...  

Supramolecular compounds have attracted considerable interest to chemists, physicists and materials scientists due to their fascinating structures and potential applications as porosity [1-3] but one of the most appealing aims today, is to build multifunctional compounds. We are interested to rationalize the synthesis of porous heterometallic compounds by self- assembly via hydrogen bonds. In this communication, we present a stacked 2D Catena-{Co(amp)3Cr(ox)3.6H2O} (amp = 2-picolylamine, ox=oxalate). It is built by layers in which both (Co(amp)3+ (D) and Cr(ox)3- ( A)) ionic units are linked in a repeating DADADA...pattern along both the a and c axis with four and two hydrogen bonds respectively. These layers host very well resolved dodecameric discrete ring water clusters (R12) built by six independent molecules located around the centrosymmetric Wyckoff position's of the P21/n space group in which the compound crystallizes. The clusters are ranged along the [001] direction, occupy 807.6 Å3 (23.9%) of the unit cell and have a chair conformation via 10 hydrogen bonds. The dehydration process of the compound occurs in one step around 77oC and the dehydrated compound remains crystalline although all framework atoms move by 2.25 Å along a mean vector (dm= 2.21 i + 0.17 j + 0.37 k) during the process. The unit cell is then reduced by 12.34 % along a, 12.22% along b and 2. 03% along c reducing V by 22.03%. By exposure to air, the regeneration of the compound needs 90 min, following the first kinetic Avrami's model.


2017 ◽  
Vol 73 (10) ◽  
pp. 820-827 ◽  
Author(s):  
Mikhail E. Minyaev ◽  
Ilya E. Nifant'ev ◽  
Alexander N. Tavtorkin ◽  
Sof'ya A. Korchagina ◽  
Shadana Sh. Zeynalova ◽  
...  

The crystal structures of rare-earth diaryl- or dialkylphosphate derivatives are poorly explored. Crystals of bis[bis(2,6-diisopropylphenyl)phosphato-κO]chloridotetrakis(methanol-κO)neodymium methanol disolvate, [Nd(C24H34O4P)Cl(CH4O)4]·2CH3OH, (1), and of the lutetium, [Lu(C24H34O4P)Cl(CH4O)4]·2CH3OH, (2), and yttrium, [Y(C24H34O4P)Cl(CH4O)4]·2CH3OH, (3), analogues have been obtained by reactions between lithium bis(2,6-diisopropylphenyl)phosphate and LnCl3(H2O)6 (in a 2:1 ratio) in methanol. Compounds (1)–(3) crystallize in the C2/c space group. Their crystal structures are isomorphous. The molecule possesses C 2 symmetry with a twofold crystallographic axis passing through the Ln and Cl atoms. The bis(2,6-diisopropylphenyl)phosphate ligands all display a κ1 O-monodentate coordination mode. The coordination polyhedron for the metal atom [coordination number (CN) = 7] is a distorted pentagonal bipyramid. Each [Ln{O2P(O-2,6-iPr2C6H3)2}2Cl(CH3OH)4] molecular unit exhibits two intramolecular O—H...O hydrogen bonds, forming six-membered rings, and two intramolecular O—H...Cl interactions, forming four-membered rings. Intermolecular O—H...O hydrogen bonds connect each unit via four noncoordinating methanol molecules with four other units, forming a two-dimensional hydrogen-bond network. Crystals of bis[bis(2,6-diisopropylphenyl)phosphato-κO]tetrakis(methanol-κO)(nitrato-κ2 O,O′)neodymium methanol disolvate, [Nd(C24H34O4P)(NO3)(CH4O)4]·2CH3OH, (4), have been obtained in an analogous manner from NdCl3(H2O)6. Compound (4) also crystalizes in the C2/c space group. Its crystal structure is similar to those of (1)–(3). The κ2 O,O′-bidentate nitrate anion is disordered over a twofold axis, being located nearly on it. Half of the molecule is crystallographically unique (CNNd = 8). Unlike (1)–(3), complex (4) exhibits disorder of all three methanol molecules, one isopropyl group of the phosphate ligand and the NO3 − ligand. The structure of (4) displays intra- and intermolecular O—H...O hydrogen bonds similar to those in (1)–(3). Compounds (1)–(4) represent the first reported mononuclear bis[bis(diaryl/dialkyl)phosphate] rare-earth complexes.


RSC Advances ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 4530-4538 ◽  
Author(s):  
Siyu He ◽  
Nan Zhang ◽  
Pu Jing

Stability of chlorophylls was improved with self-assembly of chlorophylls and NaCas nanoparticles via van der Waals forces and hydrogen bonds.


2017 ◽  
Vol 7 (6) ◽  
pp. 20160116 ◽  
Author(s):  
Xuewen Du ◽  
Jie Zhou ◽  
Xinming Li ◽  
Bing Xu

As a novel class of biomaterials, nucleopeptides, via the conjugation of nucleobases and peptides, usually self-assemble to form nanofibres driven mainly by hydrogen bonds. Containing nucleobase(s), nucleopeptides have a unique property—interacting with nucleic acids. Here we report the design and characterization of nucleopeptides that self-assemble in water and are able to interact with single-stranded DNAs (ssDNAs). Containing nucleobases on their side chains, these nucleopeptides bind with the ssDNAs, and the ssDNAs reciprocally affect the self-assembly of nucleopeptides. In addition, the interactions between nucleopeptides and ssDNAs also decrease their proteolytic resistance against proteinase K, which further demonstrates the binding with ssDNAs. The nucleopeptides also interact with plasmid DNA and deliver hairpin DNA into cells. This work illustrates a new and rational approach to create soft biomaterials by the integration of nucleobases and peptides to bind with DNA, which may lead to the development of nucleopeptides for controlling DNA in cells.


2016 ◽  
Vol 72 (1) ◽  
pp. 35-47 ◽  
Author(s):  
Katarzyna Anna Ślepokura

3′:5′-Cyclic nucleotides play an outstanding role in signal transduction at the cellular level but, in spite of comprehensive knowledge of the biological role of cyclic nucleotides, their structures are not established fully. Two hydrated sodium salts of thymidine 3′:5′-cyclic phosphate (cdTMP, C10H12N2O7P), namely sodium thymidine 3′:5′-cyclic phosphate heptahydrate, Na+·C10H12N2O7P−·7H2O or Na(cdTMP)·7H2O, (I), and sodium thymidine 3′:5′-cyclic phosphate 3.7-hydrate, Na+·C10H12N2O7P−·3.7H2O or Na(cdTMP)·3.7H2O, (II), have been obtained in crystalline form and structurally characterized, revealing one nucleotide in the asymmetric unit of (I) and eight different nucleotides in (II). All the cyclic nucleotide anions adopt a similar conformation with regard to nucleobase orientation, sugar conformation and 1,3,2-dioxaphosphorinane ring puckering. In (I), no direct inter-nucleotide hydrogen bonds are present, and adjacent nucleotide anions interactviawater-mediated and Na+-mediated contacts. In contrast, in (II), direct thymine–phosphate N—H...O inter-nucleotide hydrogen bonds occur and these are assisted by numerous inter-nucleotide C—H...O contacts, giving rise to the self-assembly of cdTMP−anions into three different ribbons. Two of these three ribbons run in the same direction, while the third is antiparallel.


2010 ◽  
Vol 65 (2) ◽  
pp. 152-156
Author(s):  
Di Sun ◽  
Cheng-Feng Yang ◽  
Zhan-Hua Wei ◽  
Geng-Geng Luo ◽  
Na Zhang ◽  
...  

A new three-dimensional (3D) supramolecular framework, [Ag2(bipy)2(bdc)·4H2O]n 1, has been synthesized by the ultrasonic reaction of Ag2O, bipy and H2bdc (H2bdc = 1,4-benzenedicarboxylic acid; bipy = 4,4’-bipyridine) at room temperature. It exhibits a new 3D supramolecular framework which is built from cationic Ag-bipy chains and anionic bdc-H2O sheets through hydrogen bonds, π · · ·π stacking and C-H· · ·π interactions. Additionally, the photoluminescent and thermal properties of 1 were investigated.


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