Natural orbital functional description of van der Waals interactions: A case study of the effect of the basis set for the helium dimer

The nature of weak van der Waals interactions in different complexes of some atmospheric molecules such as CO 2, N 2 O , and N 2 was examined. Ab initio calculation was carried out at MP2 level of theory using Dunning's aug-cc-pVTZ basis set. Bader's theory of atoms in molecules (AIM) was employed to analyze electron density and to characterize the nature and properties of van der Waals interactions. A set of criteria, having been proposed in the context of AIM theory, was examined for these complexes. In spite of the parameter kinetics energy, per electron density is expected to be greater than unity for closed-shell interactions; we obtained values less than unity for many of these polyatomic systems. A set of limitations has also been outlined for the values of two AIM quantities: total energy density, H(r), and Laplacian of electron density, ∇2ρ, which correspond to different bond natures.

Download Full-text

Structure and IR Spectroscopic Properties of HNCO Complexes with SO2 Isolated in Solid Argon

Molecules ◽

10.3390/molecules26216441 ◽

2021 ◽

Vol 26 (21) ◽

pp. 6441

Author(s):

Justyna Krupa ◽

Maria Wierzejewska ◽

Jan Lundell

Keyword(s):

Quantum Chemical ◽

Van Der Waals ◽

Spectroscopic Properties ◽

Van Der Waals Interactions ◽

Basis Set ◽

Isolation Technique ◽

The Matrix ◽

Argon Matrices ◽

Solid Argon ◽

Ir Spectroscopic

FTIR spectroscopy was combined with the matrix isolation technique and quantum chemical calculations with the aim of studying complexes of isocyanic acid with sulfur dioxide. The structures of the HNCO…SO2 complexes of 1:1, 1:2 and 2:1 stoichiometry were optimized at the MP2, B3LYPD3, B2PLYPD3 levels of theory with the 6-311++G(3df,3pd) basis set. Five stable 1:1 HNCO⋯SO2 complexes were found. Three of them contain a weak N-H⋯O hydrogen bond, whereas two other structures are stabilized by van der Waals interactions. The analysis of the HNCO/SO2/Ar spectra after deposition indicates that mostly the 1:1 hydrogen-bonded complexes are present in argon matrices, with a small amount of the van der Waals structures. Upon annealing, complexes of the 1:2 stoichiometry were detected, as well.

Download Full-text

Faculty Opinions recommendation of Direct observation of CH/CH van der waals interactions in proteins by NMR.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.732757106.793547304 ◽

2018 ◽

Author(s):

Antonio Rosato

Keyword(s):

Direct Observation ◽

Van Der Waals ◽

Van Der Waals Interactions

Download Full-text

Crystal Structures of Two New Cyclosporin Clathrates

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20001950 ◽

2000 ◽

Vol 65 (12) ◽

pp. 1950-1958 ◽

Cited By ~ 2

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).

Download Full-text

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

The Journal of Chemical Physics ◽

10.1063/5.0043615 ◽

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

Download Full-text

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

Nano Convergence ◽

10.1186/s40580-021-00262-x ◽

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.

Download Full-text

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

Materials Chemistry Frontiers ◽

10.1039/c8qm00628h ◽

2019 ◽

Vol 3 (7) ◽

pp. 1462-1470 ◽

Cited By ~ 2

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.

Download Full-text