Fascinating Supramolecular Assembly through Noncovalent Interactions Involving Anions in Organic Ionic Crystals

2021 ◽  
Vol 125 (40) ◽  
pp. 22346-22353
Author(s):  
Chen Hu ◽  
Meiyi Wang ◽  
Xiao Han ◽  
Jingyi Fan ◽  
Donghui Wei ◽  
...  
2019 ◽  
Vol 1195 ◽  
pp. 827-838 ◽  
Author(s):  
U. Likhitha ◽  
B. Narayana ◽  
B.K. Sarojini ◽  
Anupam G. Lobo ◽  
Gopal Sharma ◽  
...  

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1054
Author(s):  
Pradeep R. Varadwaj

The geometrical, energetic, noncovalent, and material properties of a catechol-based cyclic oligomer of Polyether Ether Ketone (PEEK) called o-PEEK were investigated using Molecular Dynamics (MD) and Density Functional Theory (DFT) simulations. The DFT (and MD) calculation performed with the PBEsol functional (and COMPASS II force field) gave a density of 1.39 (and 1.36) gcm−3 and a volume of 2744.5 (and 2808.5) cm3 for o-PEEK and are comparable with the corresponding experimental values of 1.328 gcm−3 and 2884.6 cm3, respectively. The absolute values of the glass transition temperature (Tg) MD simulated using the unit-cell and 2 × 2 × 2 supercell geometries of the o-PEEK system were 424.4 and 428.6 K, respectively. Although these values slightly differ from each other, both are close to the experiment (Tg = 418.2 K). The results of the (charge) density gradient analysis suggest that the supramolecular assembly between the o-PEEK oligomers in the experimentally observed infinite semi-crystal is driven by a wide range of noncovalent interactions. While the individual local interactions between the oligomers were recognized to be weak-to-medium in strength and are theoretically difficult to quantify, the B97-D3/cc-pVTZ level stabilization energy responsible for the formation of each of the five binary complex configurations extracted from the PBEsol relaxed 2 × 2 × 2 supercell geometry of the o-PEEK system was calculated to vary between –3.5 and –33.0 kcal mol−1.


2009 ◽  
Vol 64 (9) ◽  
pp. 1041-1045
Author(s):  
Eduardo E Castellano ◽  
Oscar E. Piro ◽  
Beatriz S. Parajón-Costa ◽  
Enrique J. Baran

The crystal structures of heptamethylenediammonium bis(saccharinate) monohydrate, [H3N - (CH2)7 -NH3](sac)2・H2O (1) and octamethylenediammonium bis(saccharinate) hemihydrate, [H3N- (CH2)8-NH3](sac)2・0.5H2O (2), were determined by single-crystal X-ray diffraction methods. Compound 1 crystallizes in the triclinic space group P1̄ with 2 molecules per unit cell, and 2 in the monoclinic space group P21/a with Z = 4. The saccharinate moiety is planar in both compounds presenting bonding characteristics comparable to those found in other saccharinate salts. The ionic crystals are further stabilized by an extensive H-bonding network, which links the anions and cations into an infinite three-dimensional supramolecular assembly. The FTIR spectra of the adducts are briefly discussed in comparison with those of the constituent molecules.


2020 ◽  
Author(s):  
Margaret Gerthoffer ◽  
Sikai Wu ◽  
Bo Chen ◽  
Tao Wang ◽  
Steven Huss ◽  
...  

<div><div><div><p>Limited supramolecular strategies have been utilized to synthesize sequence-defined polymers, despite the high utility of noncovalent interactions in materials design. Herein, we illustrate the utility of ‘sacrificial’ aryl-perfluoroaryl supramolecular synthons to synthesize sp3-hybridized nanothreads from sp2-enriched reactants. Our strategy features A-B reactant pairs in the form a phenol:pentafluorophenol co-crystal that is preorganized for an electronically-biased sequence-defined polymerization. The polymerization, initiated at 12 GPa, affords an alternating copolymer featuring exogenous –OH functionalities. The nanothread polymer exhibits crystallinity, as evidenced by a hexagonal X-ray diffraction pattern. The presence of the external substitution is confirmed through IR and Raman spectroscopy. Our approach realizes the first example of a functionalized sequence-defined nanothread through sacrificial supramolecular preorganization and presents a further approach for de novo design of complex nanothreads.</p></div></div></div>


2019 ◽  
Vol 75 (7) ◽  
pp. 891-903 ◽  
Author(s):  
Alfonso Castiñeiras ◽  
Isabel García-Santos ◽  
Manuel Saa

The reaction of 2-cyanopyridine with N-phenylthiosemicarbazide afforded 2-[amino(pyridin-2-yl)methylidene]-N-phenylhydrazine-1-carbothioamide (Ham4ph) and crystals of 4-phenyl-5-(pyridin-2-yl)-2,4-dihydro-3H-1,2,4-triazole-3-thione (pyph3NS, 1, C13H10N4S). Crystals of methyl 2-{[4-phenyl-5-(pyridin-2-yl)-4H-1,2,4-triazol-3-yl]sulfanyl}acetate (phpy2NS, 2, C16H14N4O2S), derived from 1, were obtained by the reaction of Ham4ph with chloroacetic acid, followed by the acid-catalyzed esterification of the carboxylic acid with methyl alcohol. Crystals of bis(methanol-κO)bis(methyl 2-{[4-phenyl-5-(pyridin-2-yl)-4H-1,2,4-triazol-3-yl-κ2 N 1,N 5]sulfanyl}acetato)zinc(II)/cadmium(II) hexabromidocadmate(II), [Zn0.76Cd0.24(C16H14N4O2S)2(CH3OH)2][Cd2Br6] or [Zn0.76Cd0.24(phpy2NS)2(MeOH)2][Cd2Br6], 3, and dichlorido(methyl 2-{[4-phenyl-5-(pyridin-2-yl)-4H-1,2,4-triazol-3-yl-κ2 N 1,N 5]sulfanyl}acetato)mercury(II), [HgCl2(C16H14N4O2S)] or [Hg(phpy2NS)Cl2], 4, were synthesized using ligand 2 and CdBr2 or HgCl2, respectively. The molecular and supramolecular structures of the compounds were studied by X-ray diffractometry. The asymmetric unit of 3 is formed from CdBr3 and M(phpy2NS)(MeOH) units, where the metal centre M has a 76% occupancy of ZnII and 24% of CdII. The M 2+ centre of the cation, located on a crystallographic inversion centre, is hexacoordinated and appears as a slightly distorted octahedral [MN4O2]2+ cation. The Cd centre of the anion is coordinated by two terminal bromide ligands and two bridging bromide ligands that generate [Cd2Br6]2− cadmium–bromide clusters. These clusters display crystallographic inversion symmetry forming two edge-shared tetrahedra and serve as agents that direct the structure in the formation of supramolecular assemblies. In mononuclear complex 4, the coordination geometry around the Hg2+ ion is distorted tetrahedral and comprises two chloride ligands and two N-atom donors from the phpy2NS ligand, viz. one pyridine N atom and the other from triazole. In the crystal packing, all four compounds exhibit weak intermolecular interactions, which facilitate the formation of three-dimensional architectures. Along with the noncovalent interactions, the structural diversity in the complexes can be attributed to the metal centre and to the coordination geometry, as well as to its ionic or neutral character.


2018 ◽  
Vol 74 (7) ◽  
pp. 816-829 ◽  
Author(s):  
Hina Andleeb ◽  
Imtiaz Khan ◽  
Antonio Bauzá ◽  
Muhammad Nawaz Tahir ◽  
Jim Simpson ◽  
...  

To explore the operational role of noncovalent interactions in supramolecular architectures with designed topologies, a series of solid-state structures of 2- and 4-formylphenyl 4-substituted benzenesulfonates was investigated. The compounds are 2-formylphenyl 4-methylbenzenesulfonate, C14H12O4S, 3a, 2-formylphenyl 4-chlorobenzenesulfonate, C13H9ClO4S, 3b, 2-formylphenyl 4-bromobenzenesulfonate, C13H9BrO4S, 3c, 4-formylphenyl 4-methylbenzenesulfonate, C14H12O4S, 4a, 4-formylphenyl 4-chlorobenzenesulfonate, 4b, C13H9ClO4S, and 4-formylphenyl 4-bromobenzenesulfonate, C13H9BrO4S, 4c. The title compounds were synthesized under basic conditions from salicylaldehyde/4-hydroxybenzaldehydes and various aryl sulfonyl chlorides. Remarkably, halogen-bonding interactions are found to be important to rationalize the solid-state crystal structures. In particular, the formation of O...X (X = Cl and Br) and type I X...X halogen-bonding interactions have been analyzed by means of density functional theory (DFT) calculations and characterized using Bader's theory of `atoms in molecules' and molecular electrostatic potential (MEP) surfaces, confirming the relevance and stabilizing nature of these interactions. They have been compared to antiparallel π-stacking interactions that are formed between the arylsulfonates.


2020 ◽  
Author(s):  
Margaret Gerthoffer ◽  
Sikai Wu ◽  
Bo Chen ◽  
Tao Wang ◽  
Steven Huss ◽  
...  

<div><div><div><p>Limited supramolecular strategies have been utilized to synthesize sequence-defined polymers, despite the high utility of noncovalent interactions in materials design. Herein, we illustrate the utility of ‘sacrificial’ aryl-perfluoroaryl supramolecular synthons to synthesize sp3-hybridized nanothreads from sp2-enriched reactants. Our strategy features A-B reactant pairs in the form a phenol:pentafluorophenol co-crystal that is preorganized for an electronically-biased sequence-defined polymerization. The polymerization, initiated at 12 GPa, affords an alternating copolymer featuring exogenous –OH functionalities. The nanothread polymer exhibits crystallinity, as evidenced by a hexagonal X-ray diffraction pattern. The presence of the external substitution is confirmed through IR and Raman spectroscopy. Our approach realizes the first example of a functionalized sequence-defined nanothread through sacrificial supramolecular preorganization and presents a further approach for de novo design of complex nanothreads.</p></div></div></div>


2018 ◽  
Vol 42 (3) ◽  
pp. 1816-1831 ◽  
Author(s):  
J. August Ridenour ◽  
Christopher L. Cahill

Presented herein are eight new binuclear uranyl complexes bridged by in situ generated peroxide ligands and assembled via noncovalent interactions.


Author(s):  
J. Petermann ◽  
G. Broza ◽  
U. Rieck ◽  
A. Jaballah ◽  
A. Kawaguchi

Oriented overgrowth of polymer materials onto ionic crystals is well known and recently it was demonstrated that this epitaxial crystallisation can also occur in polymer/polymer systems, under certain conditions. The morphologies and the resulting physical properties of such systems will be presented, especially the influence of epitaxial interfaces on the adhesion of polymer laminates and the mechanical properties of epitaxially crystallized sandwiched layers.Materials used were polyethylene, PE, Lupolen 6021 DX (HDPE) and 1810 D (LDPE) from BASF AG; polypropylene, PP, (PPN) provided by Höchst AG and polybutene-1, PB-1, Vestolen BT from Chemische Werke Hüls. Thin oriented films were prepared according to the method of Petermann and Gohil, by winding up two different polymer films from two separately heated glass-plates simultaneously with the help of a motor driven cylinder. One double layer was used for TEM investigations, while about 1000 sandwiched layers were taken for mechanical tests.


Author(s):  
U. Aebi ◽  
R. Millonig ◽  
H. Salvo

To date, most 3-D reconstructions of undecorated actin filaments have been obtained from actin filament paracrystal data (for refs, see 1,2). However, due to the fact that (a) the paracrystals may be several filament layers thick, and (b) adjacent filaments may sustantially interdigitate, these reconstructions may be subject to significant artifacts. None of these reconstructions has permitted unambiguous tracing or orientation of the actin subunits within the filament. Furthermore, measured values for the maximal filament diameter both determined by EM and by X-ray diffraction analysis, vary between 6 and 10 nm. Obviously, the apparent diameter of the actin filament revealed in the EM will critically depend on specimen preparation, since it is a rather flexible supramolecular assembly which can easily be bent or distorted. To resolve some of these ambiguities, we have explored specimen preparation conditions which may preserve single filaments sufficiently straight and helically ordered to be suitable for single filament 3-D reconstructions, possibly revealing molecular detail.


Sign in / Sign up

Export Citation Format

Share Document