Conformational analysis of coordination compounds: R-N,N,N',N'-Tetrakis-(2'-aminoethyl)-1,2-diaminopropanecobalt(III)

1967 ◽  
Vol 20 (11) ◽  
pp. 2395 ◽  
Author(s):  
JR Gollogly ◽  
CJ Hawkins
Keyword(s):  
Conformational Analysis ◽  
Metal Complexes ◽  
Coordination Compounds ◽  
A Priori ◽  
Van Der Waals ◽  
Energy Difference ◽  
Conformational Energy ◽  
Van Der Waals Interactions ◽  
Large Energy

The stereospecificity of the ligand, R-N,N,N?,N?-tetrakis(2?- aminoethyl)-1,2-diaminopropane, when coordinated as a sexadentate chelate to cobalt(III), has been investigated by an a priori calculation of the conformational energy difference between the various possible absolute configurations of the complex. It has been shown that the L isomer is more stable than the D isomer by an extremely large energy difference which is due mainly to van der Waals interactions. Some of the terms which contribute to conformational energy differences between metal complexes have not been considered previously.

Van Der Waal’s Elastica

2005 ◽  
Author(s):  
Eric Mockensturm ◽  
Arash Mahdavi
Keyword(s):  
Cross Section ◽  
Van Der Waals ◽  
Beam Theory ◽  
Van Der Waals Forces ◽  
Energy Difference ◽  
Van Der Waals Interactions ◽  
Single Atom ◽  
Experimental Investigations ◽  
Euler’S Elastica ◽  
Additional Strain

Experimental investigations of carbon nanotubes have revealed that they can collapse into nanoribbons that have a dumb-bell shape cross-section. Due to the extreme exibility of single-atom thick graphene sheets, if the tube is large enough self-induced Van der Waals forces acting on the at surfaces of the ribbon will be large enough to hold the nanotube in the collapsed (ribbon) configuration. Energetically, the additional strain (bending) energy stored in the collapsed state is offset by the decrease in energy of the Van der Waals interactions. Because Van der Waals forces are short ranged, one nds that tubes of great enough diameter are bistable. Here we investigate the natural of this bistability by investigating how the energy stored in the tube changes as it is compressed by at rigid indenters of various widths. The nanotube is assumed to deform uniformly along its length and the cross-section is modeled using inextensible, non-linear beam theory (Euler’s Elastica). We nd that the in ated (tube) conguration is always stable but that the energy barrier against decreases with increasing tube radius. Additionally, the energy difference between the in ated and collapsed states decreases nearly linear with increasing radius and for tubes with radius greater than 26 A the collapsed state is energetically favored.

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.

A comparison between approaches for the calculation of van der Waals interactions in flotation systems

2021 ◽  
Vol 167 ◽  
pp. 106804
Author(s):  
C. Weber ◽  
P. Knüpfer ◽  
M. Buchmann ◽  
M. Rudolph ◽  
U.A. Peuker
Keyword(s):  
Van Der Waals ◽  
Van Der Waals Interactions

scholarly journals 3-(2,4-Dichlorophenyl)-5-(4-fluorophenyl)-2-phenyl-7-(trifluoromethyl)pyrazolo[1,5-a]pyrimidine

2012 ◽  
Vol 68 (6) ◽  
pp. o1923-o1923
Author(s):  
Ju Liu ◽  
Zhi-Qiang Cai ◽  
Yang Wang ◽  
Yu-Li Sang ◽  
Li-Feng Xu
Keyword(s):  
Dihedral Angle ◽  
Title Compound ◽  
Phenyl Ring ◽  
Crystal Packing ◽  
Van Der Waals ◽  
Van Der Waals Interactions ◽  
Compound C ◽  
Benzene Rings ◽  
Planar Systems

In the title compound, C25H13Cl2F4N3, there are four planar systems, viz. three benzene rings and a pyrazolo[1,5-a]pyrimidine system [r.m.s. deviation = 0.002 Å]. The dihedral angle between the dichlorophenyl ring and the unsubstituted phenyl ring is 69.95 (5)°, while that between the fluorophenyl ring and the unsubstituted phenyl ring is 7.97 (10)°. The crystal packing is dominated by van der Waals interactions. A Cl...Cl interaction of 3.475 (3) Å also occurs.

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