Dipole moments induced in larger molecule. Long-chain aliphatic esters

1982 ◽  
Vol 47 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Otto Exner ◽  
Ayfer Bapçum
Keyword(s):  
Benzene Solution ◽  
Dipole Moments ◽  
Straight Chain ◽  
Basic Assumptions ◽  
Donor Acceptor ◽  
Eyring Theory ◽  
Aliphatic Esters ◽  
Long Chain

Dipole moments of straight-chain aliphatic esters Ia-Ic and IIa-IIf were measured in benzene solution. The observed trends are poorly reproduced by the classical Smith-Eyring theory; the reason may be partly the unknown conformation, partly even donor-acceptor complexes with the solvent. No deviations were observed with the highest members of the series, attributable to violation of some basic assumptions of the theory of dielectrics.

Dipole moments induced in larger molecules. 1- And 4-substituted diamantanes

1980 ◽  
Vol 45 (9) ◽  
pp. 2400-2409 ◽  
Author(s):  
Otto Exner ◽  
Václav Jehlička ◽  
Luděk Vodička ◽  
Pavel Jakoubek
Keyword(s):  
Benzene Solution ◽  
Dipole Moments ◽  
Adamantane Derivatives ◽  
Basic Assumptions ◽  
Eyring Theory

Dipole moments of fourteen monofunctional diamantane derivatives were measured in benzene solution. The values found are almost equal for 1-substituted (IIa-IIg) and 4-subtituted (IIIa to IIIg) isomers but both are distinctly higher than those of the corresponding adamantane derivatives (I). This trend is not accounted for in terms of the classic Smith-Eyring theory of induced moments which works reasonable well for smaller molecules. Probably some basic assumptions of the theory of dielectrics (a spherical molecular cavity with a dipole in its centre) are no more fulfilled for diamantane derivatives.

scholarly journals Phosphorene–Fullerene Nanostructures: A First-Principles Study

2021 ◽  
Author(s):  
Diego Cortes-Arriagada ◽  
Daniela E. Ortega
Keyword(s):  
Active Sites ◽  
Short Range ◽  
Density Functional ◽  
Dipole Moments ◽  
Molecular Size ◽  
Bandgap Engineering ◽  
Donor Acceptor ◽  
The Stability ◽  
Strong Repulsion ◽  
Intermolecular Distances

Hybrid materials formed by carbon fullerenes and layered materials have emerged due to their advantages for several technological applications, and phosphorene arises as a promising two-dimensional semiconductor for C60 adsorption. However, the properties of phosphorenefullerene hybrids remain mainly unexplored. In this work, we employed density functional theory to obtain structures, adsorption energies, electronic/optical properties, binding (AIM, NBO), and energy decomposition analyses (ALMO-EDA) of nanostructures formed by phosphorene and fullerenes (C24 to C70). We find fullerenes form covalent and non-covalent complexes with phosphorene depending on the molecular size, showing remarkable stability even in solution. Two classes of covalent complexes arise by cycloaddition-like reactions: the first class, where short-range effects (charge-transfer and polarization) determines the stability; and the second one, where short-range effects decay to avoid steric repulsion, and balanced longrange forces (electrostatics and dispersion) favors the stability. Otherwise, high-size fullerenes (C50 to C70) only form non-covalent complexes due to strong repulsion at shorter intermolecular distances and lack of dissociation barriers. In terms of electronic properties, fullerenes act as mild p-dopants for phosphorene, increasing its polar character and ability to acquire induced dipole moments (polarizability). Also, small energy-bandgap fullerenes (<0.8 eV) largely increase the phosphorene metallic character. We also note fullerenes retain their donor/acceptor properties upon adsorption, acting as active sites for orbital-controlled interactions and maximizing the phosphorene light absorbance at the UV-Vis region. Finally, we strongly believe our study will inspire future experimental/theoretical studies focused on phosphorene-fullerene uses for storage, anode materials, sensing, phosphorene bandgap engineering, and optoelectronics.<br>

Diatomite-supported Pd–M (M=Cu, Co, Ni) bimetal nanocatalysts for selective hydrogenation of long-chain aliphatic esters

2012 ◽  
Vol 386 (1) ◽  
pp. 60-65 ◽  
Author(s):  
Changliang Huang ◽  
Hongye Zhang ◽  
Yanfei Zhao ◽  
Sha Chen ◽  
Zhimin Liu
Keyword(s):  
Selective Hydrogenation ◽  
Aliphatic Esters ◽  
Long Chain ◽  
Supported Pd

Characterization of Volatile Constituents from Photomixotrophic Cell Suspension Cultures of Ruta graveolens

1984 ◽  
Vol 39 (6) ◽  
pp. 525-530 ◽  
Author(s):  
Friednch Drawert ◽  
Ralf G. Berger ◽  
Rolf Godelmann ◽  
Susanne Collin ◽  
Wolfgang Barz
Keyword(s):  
Acetic Acid ◽  
Cell Suspension ◽  
Cell Suspension Cultures ◽  
Callus Cultures ◽  
Suspension Cultures ◽  
Ruta Graveolens ◽  
Straight Chain ◽  
Methylbutyric Acid ◽  
Aliphatic Esters

Photomixotrophic cell suspension cultures of Ruta graveolens were qualitatively and quantita­tively analyzed by gaschromatography and mass spectroscopy for volatile compounds. The terpenoid hydrocarbons geijerene and pregeijerene, the C9-C13 methylketones and a series of aliphatic esters, respectively, were found as main constituents. The esters consisted of acetic acid, 2-methylbutyric acid and 3-methylbutyric acid which were esterified with straight chain or branched C8-C11 alcohols. The data are discussed in comparison to previous studies on callus cultures.

Ground and excited state dipole moments of planar vs. twisted p-N,N-(dimethylamino)benzonitrile systems: maximum charge transfer for minimum overlap

1992 ◽  
Vol 70 (7) ◽  
pp. 1932-1938 ◽  
Author(s):  
Hemant K. Sinha ◽  
S. Muralidharan ◽  
Keith Yates
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Degrees Of Freedom ◽  
Theoretical Calculations ◽  
Dipole Moments ◽  
Torsional Angle ◽  
Dimethylamino Group ◽  
Maximum Charge ◽  
Donor Acceptor ◽  
Excited State Dipole Moments

Electric field induced change in the absorption spectrum (electrochromism) has been employed to obtain the ground and excited state dipole moments of planar and sterically hindered (twisted) p-N,N-(dimethylamino)benzonitriles in dioxane solution. These studies support the twisted intramolecular charge transfer (TICT) hypothesis and provide additional insight to the TICT concept. The charge transfer nature of the excited state has been found to directly depend on the torsional angle of the N,N-dimethylamino group with respect to the benzonitrile moiety. It is suggested that solvent coupling is essential to initiate twisting by affecting the intramolecular degrees of freedom and the existence of the highly dipolar excited state is a result of such twisting of the donor–acceptor bond. Theoretical calculations have been performed to explain the observed changes in dipole moment values.

Dipole moments and conformation of α-disulphones. The gauche effect

1985 ◽  
Vol 50 (10) ◽  
pp. 2245-2251 ◽  
Author(s):  
Otto Exner ◽  
Václav Jehlička
Keyword(s):  
Dihedral Angle ◽  
Graphical Method ◽  
Benzene Solution ◽  
Dipole Moments ◽  
Statistical Treatment ◽  
X Ray ◽  
Gauche Effect

The dipole moments of substituted diphenyl disulphones I-III were measured in benzene solution and interpreted by the previously described graphical method. The results suggest an equilibrium of the ap and sc conformations in the ratio 3 : 1, at variance with various empirical rules and theories of the so-called gauche effect. A statistical treatment of X-ray data of various sulphonyl derivatives revealed essentially two preferred conformations: the more stable sc, with a broadened dihedral angle, and the less stable ap.

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