Solvation of a water molecule in cyclohexane and water

2001 ◽  
Vol 79 (2) ◽  
pp. 105-109 ◽  
Author(s):  
Giuseppe Graziano
Keyword(s):  
Experimental Data ◽  
Water Molecule ◽  
Standard Gibbs Energy ◽  
Van Der Waals ◽  
Van Der Waals Interactions ◽  
Solvent Interactions ◽  
Turn On ◽  
Standard Gibbs Energy Change ◽  
Water Solvent ◽  
Work Of Cavity Creation

Reliable values for the thermodynamic functions associated with the solvation of a water molecule in its own liquid phase and in cyclohexane, at 25°C, are obtained using experimental data from different investigations. They are successfully rationalized by means of a general theory of solvation. The standard Gibbs energy change is given by the balance of two contrasting terms: the work to create a cavity in the solvent suitable to host the water molecule; and the work to turn on the water-solvent interactions. It proves that the work of cavity creation is largely overwhelmed by the formation of two H-bonds in liquid water, whereas it is almost exactly counterbalanced by the establishment of van der Waals interactions in liquid cyclohexane.Key words: water, cavity creation, H-bonds, van der Waals interactions.

Simple Semiempirical Method of Calculating van der Waals Interactions in Thin Films from Lifshitz Theory

1976 ◽  
Vol 31 (12) ◽  
pp. 1584-1588 ◽  
Author(s):  
Chr. St. Vassilieff ◽  
I. B. Ivanov
Keyword(s):  
Experimental Data ◽  
Thin Films ◽  
Empirical Formula ◽  
Van Der Waals ◽  
Semiempirical Method ◽  
Simple Expression ◽  
Van Der Waals Interactions ◽  
Dispersion Dependence ◽  
Satisfactory Accuracy ◽  
Lifshitz Theory

AbstractThe influence of different representations of the dispersion dependence ε (i ξ) on calculating van der Waals interactions from Lifshitz theory is studied. It is shown that with satisfactory accuracy ε (i ξ) can be described by means of Krupp's empirical formula [ε (i ξ) -1]/[ε (i ξ) +1] = a · exp(-b ξ). Making use of that formula a simple expression for the Hamaker function A (h, T) is obtained. Numerical calculations are carried out, the results being compared with those of other authors and with experimental data.

Solvent-induced changes in 2J(H, F) for fluoroform via van der Waals interactions. Non-contact contributions to spin–spin coupling constants involving a proton?

1979 ◽  
Vol 57 (14) ◽  
pp. 1877-1880 ◽  
Author(s):  
Ted Schaefer ◽  
Harold M. Hutton ◽  
Salman R. Salman
Keyword(s):  
Van Der Waals ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Van Der Waals Interactions ◽  
Spin Orbital ◽  
Orbital Contribution ◽  
Solvent Interactions ◽  
Spin Coupling Constants ◽  
Induced Changes ◽  
Spin Spin Coupling

The spin–spin coupling between the proton and the fluorine nuclei, 2J, in fluoroform varies by 1% in a range of solvents. It is argued that 2J decreases algebraically as the van der Waals solute–solvent interactions increase in magnitude. Such a decrease is also observed for coupling constants which likely contain a substantial positive orbital contribution. If the van der Waals interactions perturb the spin–orbital term in J, then 2J in fluoroform may well contain orbital contributions, as recently calculated for 2J in methyl fluoride. In that event, the large discrepancies between observed 2J(H,F) values and those calculated by semiempirical theories of the contact term may be partially attributed to the neglect of orbital terms.

scholarly journals Crystal structure of a samarium(III) nitrate chain cross-linked by a bis-carbamoylmethylphosphine oxide ligand

2014 ◽  
Vol 70 (10) ◽  
pp. 188-191 ◽  
Author(s):  
Julie A. Stoscup ◽  
Richard J. Staples ◽  
Shannon M. Biros
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Water Molecule ◽  
Title Compound ◽  
Van Der Waals ◽  
Van Der Waals Interactions ◽  
Inversion Center ◽  
Nitrate Anions ◽  
Hydrogen Bonded

In the title compound poly[aquabis(μ-nitrato-κ4O,O′:O,O′′)tetrakis(nitrato-κ2O,O′){μ4-tetraethyl [(ethane-1,2-diyl)bis(azanediyl)bis(2-oxoethane-2,1-diyl)]diphosphonate-κ2O,O′}disamarium(III)], [Sm2(NO3)6(C14H30N2O8P2)(H2O)]n, a 12-coordinate SmIIIand a nine-coordinate SmIIIcation are alternately linkedviashared bis-bidentate nitrate anions into a corrugated chain extending parallel to theaaxis. The nine-coordinate SmIIIatom of this chain is also chelated by a bidentate, yet flexible, carbamoylmethylphoshine oxide (CMPO) ligand and bears one water molecule. This water molecule is hydrogen bonded to nitrate groups bonded to the 12-coordinate SmIIIcation. The CMPO ligand, which lies about an inversion center, links neighboring chains along thecaxis, forming sheets parallel to theacplane. Hydrogen bonds between the amide NH group and metal-bound nitrate anions are also present in these sheets. The sheets are packed along thebaxis through only van der Waals interactions.

scholarly journals Crystal structure of poly[μ-aqua-bis(μ3-2-methylpropanoato-κ4 O:O,O′:O′)dipotassium]

2020 ◽  
Vol 76 (10) ◽  
pp. 1669-1674
Author(s):  
Jan Fábry ◽  
Erika Samolová
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Oxygen Atom ◽  
Water Molecule ◽  
Title Compound ◽  
Van Der Waals ◽  
Van Der Waals Interactions ◽  
Compound K ◽  
Special Position ◽  
Wyckoff Position

The structure of the title compound, [K2(C4H7O2)2(H2O)] n , is composed of stacked sandwiches, which are formed by cation–oxygen bilayers surrounded by methylethyl hydrophobic chains. These sandwiches are held together by van der Waals interactions between the methylethyl groups. The methylethyl groups are disordered over two positions with occupancies 0.801 (3):0.199 (3). The potassium cations are coordinated by seven O atoms, which form an irregular polyhedron. There is a water molecule, the oxygen atom of which is situated in a special position on a twofold axis (Wyckoff position 4e). The water H atoms are involved in Owater—H...Ocarboxyl hydrogen bonds of moderate strength. These hydrogen bonds are situated within the cation–oxygen, i.e. hydrophilic, bilayer.

A Comparative Study of Adsorption of Aliphatic Amines at a Gold Electrode

2005 ◽  
Vol 70 (12) ◽  
pp. 2027-2037 ◽  
Author(s):  
Teresa Łuczak
Keyword(s):  
Gibbs Energy ◽  
Comparative Study ◽  
Gold Electrode ◽  
Surface Coverage ◽  
Standard Gibbs Energy ◽  
Gold Surface ◽  
Experimental Dependence ◽  
Aliphatic Amines ◽  
Solvent Interactions ◽  
Amine Concentration

Adsorption of aliphatic amines (C1-C4) at the gold electrode was studied by tensammetry. It has been established that the experimental dependence between the gold surface coverage (Θ) and the bulk amine concentration (cA) fits satisfactorily both by the Frumkin and Flory-Huggins isotherms. The standard Gibbs energy of adsorption, ∆G°ad at Emax for Θ < 0.8 has been found to increase in the order methylamine < ethylamine < propylamine < butylamine. This is rationalised in terms of surface-adsorbate, adsorbate-adsorbate and adsorbate-solvent interactions.

Crystal Structures of Two New Cyclosporin Clathrates

2000 ◽  
Vol 65 (12) ◽  
pp. 1950-1958 ◽  
Author(s):  
Michal Hušák ◽  
Bohumil Kratochvíl ◽  
Ivana Císařová ◽  
Alexandr Jegorov
Keyword(s):  
Crystal Structures ◽  
Methyl Ether ◽  
Van Der Waals ◽  
Van Der Waals Interactions ◽  
Solvent Molecules ◽  
Butyl Methyl Ether

Two isomorphous clathrates formed by dihydrocyclosporin A or cyclosporin V with tert-butyl methyl ether are reported and compared with the structures of related P21-symmetry cyclosporin clathrates. The cyclosporin molecules in both structures are associated via van der Waals interactions forming cavities occupied by solvent molecules (cyclosporin : tert-butyl methyl ether is 1 : 2).

Van der Waals interactions of the disulfide bond revealed: A microwave spectroscopic study of the diethyl disulfide–argon complex

2021 ◽  
Vol 154 (12) ◽  
pp. 124306
Author(s):  
Tao Lu ◽  
Daniel A. Obenchain ◽  
Jiaqi Zhang ◽  
Jens-Uwe Grabow ◽  
Gang Feng
Keyword(s):  
Spectroscopic Study ◽  
Disulfide Bond ◽  
Van Der Waals ◽  
Van Der Waals Interactions

scholarly journals Microscopic evidence of strong interactions between chemical vapor deposited 2D MoS2 film and SiO2 growth template

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Woonbae Sohn ◽  
Ki Chang Kwon ◽  
Jun Min Suh ◽  
Tae Hyung Lee ◽  
Kwang Chul Roh ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Spherical Aberration ◽  
Van Der Waals ◽  
Chemical Vapor ◽  
Interface Layer ◽  
Van Der Waals Interactions ◽  
Strong Interactions ◽  
Transition Electron Microscopy ◽  
Oxide Substrates

AbstractTwo-dimensional MoS2 film can grow on oxide substrates including Al2O3 and SiO2. However, it cannot grow usually on non-oxide substrates such as a bare Si wafer using chemical vapor deposition. To address this issue, we prepared as-synthesized and transferred MoS2 (AS-MoS2 and TR-MoS2) films on SiO2/Si substrates and studied the effect of the SiO2 layer on the atomic and electronic structure of the MoS2 films using spherical aberration-corrected scanning transition electron microscopy (STEM) and electron energy loss spectroscopy (EELS). The interlayer distance between MoS2 layers film showed a change at the AS-MoS2/SiO2 interface, which is attributed to the formation of S–O chemical bonding at the interface, whereas the TR-MoS2/SiO2 interface showed only van der Waals interactions. Through STEM and EELS studies, we confirmed that there exists a bonding state in addition to the van der Waals force, which is the dominant interaction between MoS2 and SiO2. The formation of S–O bonding at the AS-MoS2/SiO2 interface layer suggests that the sulfur atoms at the termination layer in the MoS2 films are bonded to the oxygen atoms of the SiO2 layer during chemical vapor deposition. Our results indicate that the S–O bonding feature promotes the growth of MoS2 thin films on oxide growth templates.

Concisely modularized assembling of graphene-based thin films with promising electrode performance

2019 ◽  
Vol 3 (7) ◽  
pp. 1462-1470 ◽  
Author(s):  
Weiwei Wei ◽  
Rohit L. Vekariy ◽  
Chuanting You ◽  
Yafei He ◽  
Ping Liu ◽  
...  
Keyword(s):  
Thin Films ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Double Layer ◽  
Van Der Waals ◽  
Cellulose Nanofibers ◽  
Van Der Waals Interactions ◽  
Electrode Performance ◽  
Reduced Graphene

Highly dense thin films assembled from cellulose nanofibers and reduced graphene oxide via van der Waals interactions to realize ultrahigh volumetric double-layer capacitances.

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