Conformational properties of monosubstituted cyclohexanes in their thiourea inclusion compounds and in solution: variable-temperature one-dimensional and two-dimensional carbon-13 NMR investigations

1993 ◽  
Vol 115 (14) ◽  
pp. 6369-6377 ◽  
Author(s):  
Abil E. Aliev ◽  
Kenneth D. M. Harris
Keyword(s):  
Inclusion Compounds ◽  
Variable Temperature ◽  
Two Dimensional ◽  
One Dimensional ◽  
Conformational Properties

Island decay on the anisotropic Ag(110) surface

2000 ◽  
Vol 648 ◽  
Author(s):  
Karina Morgenstern ◽  
Erik Lægsgaard ◽  
Flemming Besenbacher
Keyword(s):  
Decay Mode ◽  
Ostwald Ripening ◽  
Variable Temperature ◽  
Scanning Tunneling ◽  
Two Dimensional ◽  
Tunneling Microscopy ◽  
Sharp Transition ◽  
One Dimensional ◽  
Temperature Scanning ◽  
Rate Limiting

AbstractWe have investigated the decay of two-dimensional islands on the anisotropic Ag(110) surface using variable-temperature scanning tunneling microscopy. Contrary to predictions from traditional Ostwald ripening theory, a quasi-one-dimensional decay mode is observed at low temperatures (175-220 K). A surprisingly sharp transition to the quasi-two-dimensional decay mode is observed around 220 K. This transition is accompanied by a fast equilibration of the island shape. These findings have tentatively been rationalized within a simple model to identify the underlying rate limiting atomistic processes.

scholarly journals Structural investigation of one- and two-dimensional coordination polymers based on cobalt–bis(dioxolene) units and 1-hydroxy-1,2,4,5-tetrakis(pyridin-4-yl)cyclohexane

2018 ◽  
Vol 74 (6) ◽  
pp. 734-741 ◽  
Author(s):  
Olga Drath ◽  
Robert W. Gable ◽  
Colette Boskovic
Keyword(s):  
Coordination Polymer ◽  
Single Crystal ◽  
Coordination Polymers ◽  
Structural Investigation ◽  
Variable Temperature ◽  
Zigzag Chain ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray

The combination of cobalt, 3,5-di-tert-butyldioxolene (3,5-dbdiox) and 1-hydroxy-1,2,4,5-tetrakis(pyridin-4-yl)cyclohexane (tpch) yields two coordination polymers with different connectivities, i.e. a one-dimensional zigzag chain and a two-dimensional sheet. Poly[[bis(3,5-di-tert-butylbenzene-1,2-diolato)bis(1,5-di-tert-butyl-4-oxocyclohexa-2,5-dien-1-yl-3-olato)[μ4-1-hydroxy-1,2,4,5-tetrakis(pyridin-4-yl)cyclohexane]cobalt(III)]–ethanol–water 1/7/5], {[Co2(C14H20O2)4(C26H24N4O)]·7C2H5OH·5H2O} n or {[Co2(3,5-dbdiox)4(tpch)}·7EtOH·5H2O} n , is the second structurally characterized example of a two-dimensional coordination polymer based on linked {Co(3,5-dbdiox)2} units. Variable-temperature single-crystal X-ray diffraction studies suggest that catena-poly[[[(3,5-di-tert-butylbenzene-1,2-diolato)(1,5-di-tert-butyl-4-oxocyclohexa-2,5-dien-1-yl-3-olato)cobalt(III)]-μ-1-hydroxy-1,2,4,5-tetrakis(pyridin-4-yl)cyclohexane]–ethanol–water (1/1/5)], {[Co(C14H20O2)2(C26H24N4O)]·C2H5OH·5H2O} n or {[Co(3,5-dbdiox)2(tpch)]·EtOH·5H2O} n , undergoes a temperature-induced valence tautomeric interconversion.

N—H...S and C—H...S hydrogen bonds in two tetraalkylammonium dithiobiurea(1–) inclusion compounds

2015 ◽  
Vol 71 (4) ◽  
pp. 242-246 ◽  
Author(s):  
Hao Guo ◽  
Jinfeng Wu
Keyword(s):  
Hydrogen Bonds ◽  
Network Structure ◽  
Inclusion Compounds ◽  
Layer Structure ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Host Molecule ◽  
One Dimensional ◽  
Dimensional Network ◽  
Hydrogen Bonded

Two inclusion compounds of dithiobiurea and tetrapropylammonium and tetrabutylammonium are characterized and reported, namely tetrapropylammonium carbamothioyl(carbamothioylamino)azanide, C12H28N+·C2H5N4S2−, (1), and tetrabutylammonium carbamothioyl(carbamothioylamino)azanide, C16H36N+·C2H5N4S2−, (2). The results show that in (1), the dithiobiurea anion forms a dimerviaN—H...N hydrogen bonds and the dimers are connected into wide hydrogen-bonded ribbons. The guest tetrapropylammonium cation changes its character to become the host molecule, generating pseudo-channels containing the aforementioned ribbons by C—H...S contacts, yielding the three-dimensional network structure. In comparison, in (2), the dithiobiurea anions are linkedviaN—H...S interactions, producing one-dimensional chains which pack to generate two-dimensional hydrogen-bonded layers. These layers accommodate the guest tetrabutylammonium cations, resulting in a sandwich-like layer structure with host–guest C—H...S contacts.

A one-dimensional self-gravitating stellar gas

1966 ◽  
Vol 25 ◽  
pp. 46-48 ◽  
Author(s):  
M. Lecar
Keyword(s):  
Gravitational Field ◽  
Phase Space ◽  
Motion Picture ◽  
Space Distribution ◽  
Two Dimensional ◽  
One Dimensional ◽  
Phase Space Distribution ◽  
Dimensional Phase Space ◽  
The Mean

“Dynamical mixing”, i.e. relaxation of a stellar phase space distribution through interaction with the mean gravitational field, is numerically investigated for a one-dimensional self-gravitating stellar gas. Qualitative results are presented in the form of a motion picture of the flow of phase points (representing homogeneous slabs of stars) in two-dimensional phase space.

State-of-the-Art of Modeling Surface Water Impoundments

1982 ◽  
Vol 14 (1-2) ◽  
pp. 241-261 ◽  
Author(s):  
P A Krenkel ◽  
R H French
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
State Of The Art ◽  
Rate Coefficients ◽  
Two Dimensional ◽  
One Dimensional ◽  
Integral Energy ◽  
Range Of Values ◽  
Dimensional Integral ◽  
Water Impoundment

The state-of-the-art of surface water impoundment modeling is examined from the viewpoints of both hydrodynamics and water quality. In the area of hydrodynamics current one dimensional integral energy and two dimensional models are discussed. In the area of water quality, the formulations used for various parameters are presented with a range of values for the associated rate coefficients.

The formation of gas hydrates under shock wave impact on the bubble media (two-dimensional case)

2010 ◽  
Vol 7 ◽  
pp. 90-97
Author(s):  
M.N. Galimzianov ◽  
I.A. Chiglintsev ◽  
U.O. Agisheva ◽  
V.A. Buzina
Keyword(s):  
Shock Wave ◽  
Gas Hydrates ◽  
Hydrate Formation ◽  
Dimensional Case ◽  
Two Dimensional ◽  
Wave Impact ◽  
Bubble Liquid ◽  
One Dimensional ◽  
Bubble Media ◽  
Main Factors

Formation of gas hydrates under shock wave impact on bubble media (two-dimensional case) The dynamics of plane one-dimensional shock waves applied to the available experimental data for the water–freon media is studied on the base of the theoretical model of the bubble liquid improved with taking into account possible hydrate formation. The scheme of accounting of the bubble crushing in a shock wave that is one of the main factors in the hydrate formation intensification with increasing shock wave amplitude is proposed.

Modifications of the Godunov method for computing disturbance propagation in an elastic body

2016 ◽  
Vol 11 (1) ◽  
pp. 119-126 ◽  
Author(s):  
A.A. Aganin ◽  
N.A. Khismatullina
Keyword(s):  
Elastic Body ◽  
Godunov Method ◽  
Two Dimensional ◽  
Dimensional Problem ◽  
Order Accuracy ◽  
One Dimensional ◽  
Disturbance Propagation ◽  
Linear Waves ◽  
Longitudinal And Shear Waves ◽  
Contact Discontinuities

Numerical investigation of efficiency of UNO- and TVD-modifications of the Godunov method of the second order accuracy for computation of linear waves in an elastic body in comparison with the classical Godunov method is carried out. To this end, one-dimensional cylindrical Riemann problems are considered. It is shown that the both modifications are considerably more accurate in describing radially converging as well as diverging longitudinal and shear waves and contact discontinuities both in one- and two-dimensional problem statements. At that the UNO-modification is more preferable than the TVD-modification because exact implementation of the TVD property in the TVD-modification is reached at the expense of “cutting” solution extrema.

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