Thermodynamic and Structural Evidence for Reduced Hydrogen Bonding among Water Molecules near Small Hydrophobic Solutes

2015 ◽  
Vol 119 (36) ◽  
pp. 12108-12116 ◽  
Author(s):  
Jehoon Kim ◽  
Yun Tian ◽  
Jianzhong Wu
Keyword(s):  
Hydrogen Bonding ◽  
Water Molecules ◽  
Hydrophobic Solutes ◽  
Small Hydrophobic

scholarly journals Origin of hydrophobicity and enhanced water hydrogen bond strength near purely hydrophobic solutes

2016 ◽  
Vol 114 (2) ◽  
pp. 322-327 ◽  
Author(s):  
Joze Grdadolnik ◽  
Franci Merzel ◽  
Franc Avbelj
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Hydrophobic Hydration ◽  
Bulk Water ◽  
Water Molecules ◽  
Classical View ◽  
Fundamental Level ◽  
Hydrophobic Solute ◽  
Hydrophobic Solutes ◽  
Water Hydrogen

Hydrophobicity plays an important role in numerous physicochemical processes from the process of dissolution in water to protein folding, but its origin at the fundamental level is still unclear. The classical view of hydrophobic hydration is that, in the presence of a hydrophobic solute, water forms transient microscopic “icebergs” arising from strengthened water hydrogen bonding, but there is no experimental evidence for enhanced hydrogen bonding and/or icebergs in such solutions. Here, we have used the redshifts and line shapes of the isotopically decoupled IR oxygen–deuterium (O-D) stretching mode of HDO water near small purely hydrophobic solutes (methane, ethane, krypton, and xenon) to study hydrophobicity at the most fundamental level. We present unequivocal and model-free experimental proof for the presence of strengthened water hydrogen bonds near four hydrophobic solutes, matching those in ice and clathrates. The water molecules involved in the enhanced hydrogen bonds display extensive structural ordering resembling that in clathrates. The number of ice-like hydrogen bonds is 10–15 per methane molecule. Ab initio molecular dynamics simulations have confirmed that water molecules in the vicinity of methane form stronger, more numerous, and more tetrahedrally oriented hydrogen bonds than those in bulk water and that their mobility is restricted. We show the absence of intercalating water molecules that cause the electrostatic screening (shielding) of hydrogen bonds in bulk water as the critical element for the enhanced hydrogen bonding around a hydrophobic solute. Our results confirm the classical view of hydrophobic hydration.

scholarly journals Hydration of Biological Macromolecules: From Small Solutes to Proteins and Nucleic Acids

1996 ◽  
Vol 463 ◽  
Author(s):  
Shekhar Garde ◽  
Gerhard Hummer ◽  
Michael E. Paulaitis ◽  
Angel E. Garcia
Keyword(s):  
Potential Of Mean Force ◽  
Water Molecules ◽  
Biological Macromolecules ◽  
Particle Correlation ◽  
X Ray ◽  
X Ray Crystallography ◽  
Catabolite Activator Protein ◽  
Hydrophobic Solutes ◽  
Small Hydrophobic ◽  
Good Agreement

We present a method that uses two- and three-particle correlation functions between solute atoms and water molecules to approximate the density profile of water surrounding biomolecules. The method is based on a potential of mean force expansion and uses X-ray crystallography, NMR, or modeling structural input information on the biomolecule. For small hydrophobic solutes, we have calculated entropies of hydration using the predicted water densities that are in good agreement with experimental results. We have also predicted the hydration of thecatabolite activator protein-DNAcomplex. The method is extremely efficient and makes possible the study of hydration of large biomolecules within CPU minutes.

PEMANFAATAN GLISERIN DARI RESIDU GLISERIN SEBAGAI PLASTICIZER UNTUK PEMBUATAN BIOPLASTIK DENGAN BAHAN BAKU PATI BONGGOL PISANG KEPOK

2017 ◽  
Vol 5 (4) ◽  
pp. 26-32 ◽  
Author(s):  
Azaria Robiana ◽  
M. Yashin Nahar ◽  
Hamidah Harahap
Keyword(s):  
Tensile Strength ◽  
Hydrogen Bonding ◽  
Fatty Acid ◽  
Maximum Yield ◽  
Sem Analysis ◽  
Water Molecules ◽  
Banana Weevil ◽  
Gelatinization Temperature ◽  
Recharge Area ◽  
Maximum Quantity

Glycerin residue is waste oleochemical industry that still contain glycerin. To produce quality and maximum quantity of glycerin, then research the effect of pH acidification using phosphoric acid. Glycerin analysis includes the analysis of pH, Fatty Acid and Ester (FAE), and analysis of the levels of glycerin. The maximum yield obtained at pH acidification 2 is grading 91,60% glycerin and Fatty Acid and Ester (FAE) 3,63 meq/100 g. Glycerin obtained is used as a plasticizer in the manufacture of bioplastics. Manufacture of bioplastics using the method of pouring a solution with varying concentrations of starch banana weevil (5% w/v and 7% w/v), variations of the addition of glycerin (1 ml, 3 ml, 5 ml and 7 ml), and a variety of gelatinization temperature (60°C, 70°C, and 80°C). Analysis of bioplastics include FTIR testing, tensile strength that is supported by SEM analysis. The results obtained in the analysis of FTIR does not form a new cluster on bioplastics starch banana weevil, but only a shift in the recharge area only, it is due to the addition of O-H groups originating from water molecules that enter the polysaccharide through a mechanism gelatinitation that generates interaction hydrogen bonding strengthened. The maximum tensile strength of bioplastics produced at a concentration of starch 7% w/v, 1 ml glycerine and gelatinization temperature of 80°C is 3,430 MPa. While the tensile strength bioplastic decreased with increasing glycerin which can be shown from the results of SEM where there is a crack, indentations and lumps of starch insoluble.

Study on the effect of protein buffer solution on hydrogen bonding of water molecules based on terahertz metamaterial absorber

Optik ◽  
2021 ◽  
Vol 238 ◽  
pp. 166771
Author(s):  
Jianjun Liu ◽  
Tiejun Li ◽  
Senquan Yan ◽  
Haoxiang Wen ◽  
Fan Ding
Keyword(s):  
Hydrogen Bonding ◽  
Metamaterial Absorber ◽  
Water Molecules ◽  
Buffer Solution

A New Organic-Inorganic Hybrid Based on L-Arginine and Polyoxoanion

2015 ◽  
Vol 1105 ◽  
pp. 335-338
Author(s):  
Qiong Wu ◽  
Jing Lu ◽  
Xiao Lin Ji ◽  
Tao Yu Zou ◽  
Zhen Fang Qiao ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Sodium Cation ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Inorganic Hybrid ◽  
X Ray ◽  
Hydrogen Bonding Interactions ◽  
Photocatalytic Activities ◽  
Metal Organic ◽  
Supramolecular Networks

Modifying polyoxometalates with organic and/or metal-organic moieties is a widely adopted method for broading the range of properties. In this work a new polyoxometalate constructed from Anderson-type polyoxoanions and L-arginine (Arg =L-arginine) molecules Na [CrMo6(OH)6O18]}(H2Arg)2·8H2O(1) has been synthesized via conventional method and characterized by routine techniques. Single-crystal X-Ray diffraction analysis shows that compound 1 is constructed by chiralL-arginine grafted Anderson-type clusters, sodium cation and water molecules which are further stabilized by hydrogen bonding interactions constitute 3D supramolecular networks. In addition, both antitumor behavior and photocatalytic activities of compound 1 were investigated.

scholarly journals Pentaaqua(1H-benzimidazole-5,6-dicarboxylato-κN3)cobalt(II) pentahydrate

2009 ◽  
Vol 65 (6) ◽  
pp. m702-m702 ◽  
Author(s):  
Wen-Dong Song ◽  
Hao Wang ◽  
Shi-Jie Li ◽  
Pei-Wen Qin ◽  
Shi-Wei Hu
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Organic Ligand ◽  
Octahedral Geometry ◽  
Mononuclear Complex ◽  
Distorted Octahedral Geometry ◽  
Water Molecules ◽  
Supramolecular Network ◽  
Hydrogen Bonding Interactions ◽  
Distorted Octahedral

In the title mononuclear complex, [Co(C9H4N2O4)(H2O)5]·5H2O, the CoIIatom exhibits a distorted octahedral geometry involving an N atom of a 1H-benzimidazole-5,6-dicarboxylate ligand and five water O atoms. A supramolecular network is generated through intermolecular O—H...O hydrogen-bonding interactions involving the coordinated and uncoordinated water molecules and the carboxyl O atoms of the organic ligand. An intermolecular N—H...O hydrogen bond is also observed.

scholarly journals Structure and hydrogen bonding of the hydrated selenite and selenate ions in aqueous solution

2014 ◽  
Vol 43 (17) ◽  
pp. 6315-6321 ◽  
Author(s):  
Lars Eklund ◽  
Ingmar Persson
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Bonding ◽  
Free Electron ◽  
Electron Pair ◽  
Bound Water ◽  
Water Molecules ◽  
Hydration Sphere ◽  
Free Electron Pair

The selenite ion has an asymmetric hydration sphere with loosely electrostatically bound water molecules outside the free electron pair.

scholarly journals Two New Polyiodides in the 4,4´-Bipyridinium Diiodide/Iodine System

2012 ◽  
Vol 67 (1) ◽  
pp. 5-10
Author(s):  
Guido J. Reiss ◽  
Martin van Megen
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Complex I ◽  
The Other ◽  
Cyclic Dimer ◽  
Water Molecules ◽  
Spectroscopic Methods ◽  
Halogen Bonds ◽  
One Dimensional ◽  
Hydroiodic Acid

The reaction of bipyridine with hydroiodic acid in the presence of iodine gave two new polyiodide-containing salts best described as 4,4´-bipyridinium bis(triiodide), C10H10N2[I3]2, 1, and bis(4,4´-bipyridinium) diiodide bis(triiodide) tris(diiodine) solvate dihydrate, (C10H10N2)2I2[I3]2 · 3 I2 ·2H2O, 2. Both compounds have been structurally characterized by crystallographic and spectroscopic methods (Raman and IR). Compound 1 is composed of I3 − anions forming one-dimensional polymers connected by interionic halogen bonds. These chains run along [101] with one crystallographically independent triiodide anion aligned and the other triiodide anion perpendicular to the chain direction. There are no classical hydrogen bonds present in 1. The structure of 2 consists of a complex I144− anion, 4,4´-bipyridinium dications and hydrogen-bonded water molecules in the ratio of 1 : 2 : 2. The I144− polyiodide anion is best described as an adduct of two iodide and two triiodide anions and three diiodine molecules. Two 4,4´-bipyridinium cations and two water molecules form a cyclic dimer through N-H· · ·O hydrogen bonds. Only weak hydrogen bonding is found between these cyclic dimers and the polyiodide anions.

Sign in / Sign up

Export Citation Format

Share Document