Interplay between Halogen/Hydrogen Bonding and Electrostatic Interactions in 1,1′-Bis(4-iodobenzyl)-4,4′-bipyridine-1,1′-diium Salts

2009 ◽  
Vol 9 (12) ◽  
pp. 5009-5013 ◽  
Author(s):  
Marcos D. García ◽  
Víctor Blanco ◽  
Carlos Platas-Iglesias ◽  
Carlos Peinador ◽  
José M. Quintela
Keyword(s):  
Hydrogen Bonding ◽  
Electrostatic Interactions

Influence of Electrostatic Interactions and Hydrogen Bonding on the Activity of Cyclodextrin-based Superoxide Dismutase Models

2001 ◽  
Vol 13 (5) ◽  
pp. 619-625 ◽  
Author(s):  
Alex Fragoso ◽  
Roberto Cao ◽  
Alicia Díz ◽  
Ileana Sånchez ◽  
Leticia Sånchez
Keyword(s):  
Superoxide Dismutase ◽  
Hydrogen Bonding ◽  
Electrostatic Interactions

scholarly journals The N-atom in [N(PR3)2]+ cations (R = Ph, Me) can act as electron donor for (pseudo) anti-electrostatic interactions

CrystEngComm ◽  
2015 ◽  
Vol 17 (20) ◽  
pp. 3768-3771 ◽  
Author(s):  
Antonio Bauzá ◽  
Antonio Frontera ◽  
Tiddo J. Mooibroek ◽  
Jan Reedijk
Keyword(s):  
Hydrogen Bonding ◽  
Electron Donor ◽  
Molecular Hydrogen ◽  
Electrostatic Interactions ◽  
Lone Pair ◽  
Dft Study ◽  
Nitrogen Lone Pair

A CSD analysis and DFT study reveal that the nitrogen lone-pair in [N(PPh3)2]+ is partially intact and involved in intramolecular hydrogen bonding.

The Structure and Properties of Water

2016 ◽  
Author(s):  
Bruce C. Bunker ◽  
William H. Casey
Keyword(s):  
Hydrogen Bonding ◽  
Water Molecule ◽  
Bond Length ◽  
Electrostatic Interactions ◽  
Structure And Properties ◽  
Oxygen Anion ◽  
Lone Pairs ◽  
Tetrahedral Angle ◽  
Oxide Phases ◽  
Single Water Molecule

Water is one of the most complex fluids on Earth. Even after intense study, there are many aspects regarding the structure, properties, and chemistry of water that are not well understood. In this chapter, we highlight the attributes of water that dictate many of the reactions that take place between water and oxides. We start with a single water molecule and progress to water clusters, then finally to extended liquid and solid phases. This chapter provides a baseline for evaluating what happens when water encounters simple ions, soluble oxide complexes called hydrolysis products, and extended oxide phases. The primary phenomenon highlighted in this chapter is hydrogen bonding. Hydrogen bonding dominates the structure and properties of water and influences many water–oxide interactions. A single water molecule has eight valence electrons around a central oxygen anion. These electrons are contained in four sp3-hybridized molecular orbitals arranged as lobes that extend from the oxygen in a tetrahedral geometry. Each orbital is occupied by two electrons. Two of the lobes are bonded to protons; the other two lobes are referred to as lone pairs of electrons. The H–O–H bond angle of 104.5° is close to the tetrahedral angle of 109.5°. The O–H bond length in a single water molecule is 0.96 Ǻ. It is important to recognize that this bond length is really a measure of the electron density associated with the oxygen lone pair bonded to the proton. This is because a proton is so incredibly small (with an ionic radius of only 1.3·10−5 Ǻ) that it makes no contribution to the net bond length. The entire water molecule has a hard sphere diameter of 2.9 Ǻ, which is fairly typical for an oxygen anion. This means the unoccupied lone pairs are distended relative to the protonated lone pairs, extending out to roughly 1.9 Ǻ. The unequal distribution of charges introduces a dipole within the water molecule that facilitates electrostatic interactions with other molecules.

Three-dimensional hydrogen bonding between Landers and planar molecules facilitated by electrostatic interactions with Ni adatoms

2018 ◽  
Vol 54 (64) ◽  
pp. 8845-8848 ◽  
Author(s):  
Miao Yu ◽  
Youness Benjalal ◽  
Chong Chen ◽  
Nataliya Kalashnyk ◽  
Wei Xu ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Electrostatic Interactions ◽  
Molecular System ◽  
Three Dimensional ◽  
Planar Molecules ◽  
Self Assembled

Ni adatoms are at the origin of a self-assembled bicomponent molecular system on Au(111).

Stabilization of Hydrogen-Bonded Poly(N-isopropylacrylamide) Multilayers by a Dual Electrostatic/Hydrogen Bonding Copolymer

2005 ◽  
Vol 58 (6) ◽  
pp. 442 ◽  
Author(s):  
John F. Quinn ◽  
Frank Caruso
Keyword(s):  
Thin Films ◽  
Hydrogen Bonding ◽  
Electrostatic Interactions ◽  
Ph Stability ◽  
Multilayer Thin Films ◽  
Film Morphology ◽  
Styrene Sulfonate ◽  
Allylamine Hydrochloride ◽  
Multilayer Assemblies ◽  
Poly Styrene Sulfonate

Multilayer thin films were prepared based on hydrogen bonding between poly(N-isopropylacrylamide) (PNiPAAm), and poly(styrene sulfonate-co-maleic acid) (PSSMA). Since PSSMA is capable of associating with other polymers through both hydrogen bonding and electrostatic interactions, multilayer assemblies incorporating PSSMA, PNiPAAm, and intercalated poly(allylamine hydrochloride) (PAH) layers were also prepared. Intercalated PAH layers were included to improve the pH stability of the film by introducing electrostatic linkages into the assembly. Film construction was studied as a function of pH of the deposition solution and the number of inserted PAH layers. Film morphology varied significantly with incorporation of PAH into the film. It was also demonstrated that by intercalating several PAH layers within the PNiPAAm/PSSMA assembly, the pH stability of the films at pH 5.8 could be substantially improved.

scholarly journals Bis[μ-N,N′-(pyridine-2,6-diyl)bis(trimethylsilylamido)-1κ2N1,N2;2:3κ2N6:N6]bis(tetrahydrofuran)-2:3κ2O-1-nickel(II)-2,3-lithium(I)

IUCrData ◽  
2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Alan M. Boltin ◽  
Gary L. Guillet
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Electrostatic Interactions ◽  
Rotational Symmetry ◽  
Title Complex ◽  
Planar Geometry ◽  
Intermolecular Hydrogen Bonding ◽  
Trimethylsilyl Group ◽  
Square Planar ◽  
Dominant Feature

The title complex, [Li2Ni(C11H21N3Si2)2(C4H8O)2], is a trimetallic complex of two LiIcations and a NiIIcation bridged by twoN,N′-(pyridine-2,6-diyl)bis(trimethylsilylamide) ligands that crystallizes in theFdd2 space group. The molecule hasC2rotational symmetry, with the NiIIcation located on the twofold axis. The coordination sphere of the NiIIcation is composed of two amido N and two pyridyl N-atom donors in a distorted square-planar geometry. The LiIcations are coordinated by two amido N-atom donors and a tetrahydrofuran molecule with a long interaction with a pyridyl N-atom donor. The coordinating tetrahydrofuran ligand and a trimethylsilyl group are disordered. Intra- or intermolecular hydrogen bonding, as well as π–π stacking, are not observed between the molecules, likely indicating that weak electrostatic interactions are the dominant feature leading to the crystal structure.

scholarly journals Potential of Kale and Lettuce Residues as Natural Adsorbents of the Carcinogen Aflatoxin B1 in a Dynamic Gastrointestinal Tract-Simulated Model

Toxins ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 771
Author(s):  
Alma Vázquez-Durán ◽  
María de Jesús Nava-Ramírez ◽  
Daniel Hernández-Patlán ◽  
Bruno Solís-Cruz ◽  
Víctor Hernández-Gómez ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Gastrointestinal Tract ◽  
Aflatoxin B1 ◽  
Electrostatic Interactions ◽  
Hydrophobic Interactions ◽  
Maximum Adsorption Capacity ◽  
Promising Alternative ◽  
Simulated Model ◽  
Dipole Interactions ◽  
Natural Adsorbents

Adsorption of the carcinogen aflatoxin B1 (AFB1) onto agro-waste-based materials is a promising alternative over conventional inorganic binders. In the current study, two unmodified adsorbents were eco-friendly prepared from kale and lettuce agro-wastes. A dynamic gastrointestinal tract-simulated model was utilized to evaluate the removal efficiency of the sorptive materials (0.5%, w/w) when added to an AFB1-contaminated diet (100 µg AFB1/kg). Different characterization methodologies were employed to understand the interaction mechanisms between the AFB1 molecule and the biosorbents. Based on adsorption results, the biosorbent prepared from kale was the best; its maximum adsorption capacity was 93.6%, which was significantly higher than that of the lettuce biosorbent (83.7%). Characterization results indicate that different mechanisms may act simultaneously during adsorption. Non-electrostatic (hydrophobic interactions, dipole-dipole interactions, and hydrogen bonding) and electrostatic interactions (ionic attractions) together with the formation of AFB1-chlorophyll complexes appear to be the major influencing factors driving AFB1 biosorption.

scholarly journals Collaborative Behavior of Urea and KI in Denaturing Protein Native Structure

2019 ◽  
Author(s):  
Qiang Shao ◽  
Jinan Wang ◽  
Weiliang Zhu
Keyword(s):  
Molecular Dynamics ◽  
Hydrogen Bonding ◽  
Structural Dynamics ◽  
Electrostatic Interactions ◽  
Side Chain ◽  
Mixed Solution ◽  
Native Structure ◽  
Indirect Influence ◽  
Collaborative Behavior ◽  
Dynamics Simulations

AbstractIn this work, the combined influence of urea and KI on protein native structure is quantitatively investigated through the comparative molecular dynamics simulations on the structural dynamics of a polypeptide of TRPZIP4 in a series of urea/KI mixed solutions (urea concentration: 4M, KI salt concentration: 0M-6M). The observed enhanced denaturing ability of urea/KI mixture can be explained by direct interactions of urea/K+/water towards protein (electrostatic and vdW interactions from urea and electrostatic interactions from K+ and water) and indirect influence of KI on the strengthened interaction of urea towards protein backbone and side-chain. The latter indirect influence is fulfilled through the weakening of hydrogen bonding network among urea and water by the appearance of K+–water and I—urea interactions. As a result, the denaturing ability enhancement of urea and KI mixed solution is induced by the collaborative behavior of urea and KI salt.

In Silico Structure Modeling and Molecular Docking Analysis of Phosphoribosyl Pyrophosphate Amidotransferase (PPAT) with Antifolate Inhibitors

2019 ◽  
Vol 19 (5) ◽  
pp. 408-416 ◽  
Author(s):  
Nousheen Bibi ◽  
Zahida Parveen ◽  
Muhammad Sulaman Nawaz ◽  
Mohammad Amjad Kamal
Keyword(s):  
Hydrogen Bonding ◽  
Molecular Docking ◽  
Active Site ◽  
Electrostatic Interactions ◽  
De Novo ◽  
Cancer Therapeutics ◽  
Purine Biosynthesis ◽  
Biosynthesis Pathway ◽  
Phosphoribosyl Pyrophosphate ◽  
De Novo Purine Biosynthesis

Background: Cancer remains one of the most serious disease worldwide. Robust metabolism is the hallmark of cancer. PPAT (phosphoribosyl pyrophosphate amidotransferase) catalyzes the first committed step of de novo purine biosynthesis. Hence PPAT, the key regulatory spot in De novo purine nucleotide biosynthesis, is an attractive and credible drug target for leukemia and other cancer therapeutics. Objective: In the present study, detailed computational analysis has been performed for PPAT protein, the key enzyme in de novo purine biosynthesis which is inhibited by many folate derivatives, hence we aimed to investigate and gauge the inhibitory effect of antifolate derivatives; lomexterol (LTX) methotrexate (LTX), and pipretixin (PTX) with human PPAT to effectively capture and inhibit De novo purine biosynthesis pathway. Methods: The sequence to structure computational approaches followed by molecular docking experiments was performed to gain insight into the inhibitory mode, binding orientation and binding affinities of selected antifolate derivatives against important structural features of PPAT. Results: Results indicated a strong affinity of antifolate inhibitors for the conserved active site of PPAT molecule encompassing a number of hydrophobic, hydrogen bonding, Vander Waals and electrostatic interactions. Results: Results indicated a strong affinity of antifolate inhibitors for the conserved active site of PPAT molecule encompassing a number of hydrophobic, hydrogen bonding, Vander Waals and electrostatic interactions. Conclusion: Conclusively, the strong physical interaction of selected antifolate inhibitors with human PPAT suggests the selective inhibition of De novo purine biosynthesis pathway by antifolate derivatives towards cancer therapeutics.

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