Search results for "intermolecular interaction"
showing 10 items of 32 documents
Brownian dynamics simulation of grafted polymer brushes
1995
We present results of computer simulations by the method of Brownian dynamics of polymeric brushes attached to impenetrable planes. For testing both model and method we have used one polymer brush attached to a repulsive plane and compare some results with Monte Carlo results of Lai and Binder on the bond fluctuation model. We have also studied two polymeric brushes attached to two parallel planes at different distances between planes, and investigate the interplay between the interpenetration of the brushes and the configurational properties of the grafted chains.
Crystal structure, Hirshfeld surface analysis and HOMO–LUMO analysis of (E)-4-bromo-N′-(4-methoxybenzylidene)benzohydrazide
2018
The title Schiff base compound, C15H13BrN2O2, displays an E configuration with respect to the C=N double bond, which forms a dihedral angle of 58.06 (9)° with the benzene ring. In the crystal, the molecules are linked into chains parallel to the b axis by N—H...O and C—H...O hydrogen bonds, giving rise to rings with an R 2 1(6) graph-set motif. The chains are further linked into a three-dimensional network by C—H...π interactions. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from C...H (33.2%), H...H (27.7%), Br...H/H...Br (14.2%) and O...H/H...O (13.6%) interactions. The title compound has also been characterized by frontier molecu…
Crystal structure, Hirshfeld surface analysis and HOMO–LUMO analysis of (E)-N′-(3-hydroxy-4-methoxybenzylidene)nicotinohydrazide monohydrate
2019
The title Schiff base compound displays an E configuration with respect to the C=N double bond. The pyridine and benzene rings subtend a dihedral angle of 29.63 (7)°. In the crystal, the molecules are linked by N—H⋯O, C—H⋯O, O—H⋯O and O—H⋯N hydrogen-bonding interactions.
Intramolecular 1,5-S...N σ-hole interaction in (E)-N′-(pyridin-4-ylmethylidene)thiophene-2-carbohydrazide
2020
The hydrazide-hydrazone forms inverse dimers via hydrogen bonding, but its conformation is defined by the presence of an intramolecular chalcogen bond. Electrostatic forces dominate in the crystal packing and give rise to a layered supramolecular structure.
Bis{4-[(2-hydroxy-5-methoxy-3-nitrobenzylidene)amino]phenyl} ether
2020
The molecule of the title oxybis compound lies on a twofold rotational axis. The conformation of the title compound is discussed and compared to those of related structures. In the crystal, molecules of the title compound are assembled into layers parallel to the ab plane through C—H⋯O hydrogen bonds.
The Effect of the Side Chain on Gelation Properties of Bile Acid Alkyl Amides
2021
Abstract Six bile acid alkyl amide derivatives were studied with respect to their gelation properties. The derivatives were composed of three different bile acids with hexyl or cyclohexyl side chains. The gelation behaviour of all six compounds were studied for 36 solvents with varying polarities. Gelation was observed mainly in aromatic solvents, which is characteristic for bile‐acid‐based low molecular weight gelators. Out of 108 bile acid‐solvent combinations, a total of 44 gel systems were formed, 28 of which from lithocholic acid derivatives, only two from deoxycholic acid derivatives, and 14 from cholic acid derivatives. The majority of the gel systems were formed from bile acids with…
Halogen Bonds in Square Planar 2,5-Dihalopyridine-Copper(II) Bromide Complexes
2018
Experimental FTIR-MI and Theoretical Studies of Isocyanic Acid Aggregates
2023
Homoaggregates of isocyanic acid (HNCO) were studied using FTIR spectroscopy combined with a low-temperature matrix isolation technique and quantum chemical calculations. Computationally, the structures of the HNCO dimers and trimers were optimized at the MP2, B3LYPD3 and B2PLYPD3 levels of theory employing the 6-311++G(3df,3pd) basis set. Topological analysis of the electron density (AIM) was used to identify the type of non-covalent interactions in the studied aggregates. Five stable minima were located on the potential energy surface for (HNCO)2, and nine were located on the potential energy surface for (HNCO)3. The most stable dimer (D1) involves a weak, almost linear N-H⋯N hydrog…
Self-assembly mechanism based on charge density topological interaction energies
2017
The packing interactions have been evaluated in the context of the self-assembly mechanism of crystal growth and also for its impacts on the aromaticity of the trimesate anion. The structure of ethylammonium trimesate hydrate (1) measured at 100 K and a charge density model, derived in part from theoretical structures, is reported. Theoretical structure factors were obtained from the geometry-optimized periodic wave function. The trimesic acid portion of 1 is fully deprotonated and participates in a variety hydrogen bonding motifs. Topological analysis of the charge density model reveals the most significant packing interactions and is then compared to a complementary analysis performed by …
Halogen Bonds in Square Planar 2,5-Dihalopyridine-Copper(II) Bromide Complexes
2018
Halogen bonding in self-complementary 1:2 metal–ligand complexes obtained from copper(II) bromide (CuBr2) and seven 2,5-dihalopyridines were analyzed using single-crystal X-ray diffraction. All presented discrete complexes form 1D polymeric chains connected with C–X···Br–Cu halogen bonds (XB). In (2-chloro-5-X-pyridine)2·CuBr2 (X = Cl, Br, and I) only the C5-halogen and in (2-bromo-5-X-pyridine)2·CuBr2 (X = Cl, Br, and I) both C2- and C5-halogens form C–X···Br–Cu halogen bonds with the X acting as the XB donor and copper-coordinated bromide as the XB acceptor. The electron-withdrawing C2-chloride in (2-chloro-5-X-pyridine)2·CuBr2 complexes has only a minor effect on the C5–X5···Br–Cu XBs, a…