Enthalpies of transfer of aliphatic compounds from vapor to solvents. Steric hindrance to functional group solvation

1976 ◽  
Vol 54 (24) ◽  
pp. 3857-3859 ◽  
Author(s):  
Richard Fuchs ◽  
Preetpal S. Saluja
Keyword(s):  
Steric Hindrance ◽  
Functional Group ◽  
Dipole Interaction ◽  
Ethylenic Bond ◽  
Aliphatic Compounds ◽  
Enthalpies Of Transfer ◽  
Tert Butyl ◽  
Induced Dipole ◽  
Butyl Ketone

Enthalpies of transfer from the vapor to solution (ΔH(v → S)) in cyclohexane are similar for alkenes and the corresponding alkanes. The transfer from vapor to dimethylformamide is about 0.6 kcal/mol more exothermic for 1-alkenes, which results from the dipole-induced dipole interaction of the solvent dipole with the π system. When the ethylenic bond is hindered by large adjacent groups (trans-1,2-di-tert-butylethylene) to the approach of solvent dipoles, ΔH(v → DMF) becomes similar to that of the corresponding alkane (1,2-di-tert-butylethane). Similarly the interaction of di-tert-butyl ketone with DMF is 0.7 kcal/mol weaker than that of the less hindered isomer, 2-nonanone.

Tri(tert-butyl)phosphinoxid, -imin, -methylen und -boran / Tri(tert-butyl)phosphine Oxide, Imine, Methylene and Borane

1978 ◽  
Vol 33 (12) ◽  
pp. 1556-1558 ◽  
Author(s):  
Hubert Schmidbaur ◽  
Günter Blaschke
Keyword(s):  
Thermal Decomposition ◽  
Phosphine Oxide ◽  
Steric Hindrance ◽  
Reductive Elimination ◽  
Tert Butyl

Abstract Tri(tert-butyl)phosphine Oxide, Imine, Methylene, Borane Tri(tert-butyl)phosphine oxide, imine, methylene and borane have been prepared and their properties investigated. The imine is chemically inert due to strong steric hindrance. Its thermal decomposition at 200 °C leads to tri(tert-butyl)-pliosphine, in contrast to the methylene analogue which undergoes reductive elimination of isobutene. Both the oxide and borane are thermally very stable (> 250 °C).

Limiting activity coefficients in dilute solutions of nonelectrolytes. II. Determination for polar–nonpolar and polar–polar binary mixtures, and the application of some solubility-parameter treatments

1986 ◽  
Vol 64 (1) ◽  
pp. 198-203 ◽  
Author(s):  
Shapour Afrashtehfar ◽  
Genille C. B. Cave
Keyword(s):  
Binary Mixture ◽  
Activity Coefficients ◽  
Vapor Phase ◽  
Solubility Parameter ◽  
Chromatographic Analysis ◽  
Dipole Interaction ◽  
The Other ◽  
Binary Solutions ◽  
Polar Components ◽  
Induced Dipole

Activity coefficients were determined at 293.15 K for the more dilute component in 24 binary solutions of nonelectrolytes, by gas-chromatographic analysis of the equilibrium vapor phase. One component of the binary mixture was either nitromethane, nitroethane, 1-nitropropane, 2-nitropropane, ethanenitrile, propanenitrile, ethyl ethanoate, or butyl ethanoate; and the other component was either heptane, 1-heptene, or 1,6-heptadiene.From the limiting activity coefficients of these components, some factors that affected their magnitude were identified. The values were also used to test the modifications of Prausnitz, Blanks, and Weimer, of Helpinstill and Van Winkle, and of Keller, Karger, and Snyder to the Scatchard–Hildebrand equation modified to accommodate polar components. In addition, the degree of constancy of the ratio of the dipole – induced dipole interaction parameter for a series of solutes in one solvent to that in another was considered.

Hydrophobic Carbon Dots from Aliphatic Compounds with One Terminal Functional Group

2019 ◽  
Vol 123 (36) ◽  
pp. 22447-22456 ◽  
Author(s):  
Keyang Yin ◽  
Dandan Lu ◽  
Liping Wang ◽  
Quanxin Zhang ◽  
Junying Hao ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Functional Group ◽  
Aliphatic Compounds ◽  
Terminal Functional Group

HYDROGEN STORAGE ON NANOFULLERENE CAGES

NANO ◽  
2009 ◽  
Vol 04 (05) ◽  
pp. 253-263 ◽  
Author(s):  
NATARAJAN SATHIYAMOORTHY VENKATARAMANAN ◽  
HIROSHI MIZUSEKI ◽  
YOSHIYUKI KAWAZOE
Keyword(s):  
Hydrogen Storage ◽  
Dipole Interaction ◽  
Binding Energies ◽  
Reversible System ◽  
Storage Medium ◽  
Transition Elements ◽  
Practical Applications ◽  
Alkali Earth ◽  
Induced Dipole ◽  
A Charge

In this paper, we discuss and compare various nanocage materials proposed theoretically as storage medium for hydrogen. Doping of transition elements leads to clustering which reduces the gravimetric density of hydrogen, while doping of alkali and alkali-earth metals on the nanocage materials, such as carborides, boronitride, and boron cages, were stabilized by the charger transfer from the dopant to the nanocage. Further, the alkali or alkali-earth elements exist with a charge, which are found to be responsible for the higher uptake of hydrogen, through a dipole–dipole and change-induced dipole interaction. The binding energies of hydrogen on these systems were found to be in the range of 0.1 eV to 0.2 eV, which are ideal for the practical applications in a reversible system.

scholarly journals Experimental quantification of contact freezing in an electrodynamic balance

2013 ◽  
Vol 6 (9) ◽  
pp. 2373-2382 ◽  
Author(s):  
N. Hoffmann ◽  
A. Kiselev ◽  
D. Rzesanke ◽  
D. Duft ◽  
T. Leisner
Keyword(s):  
Average Rate ◽  
Aerosol Particles ◽  
Dipole Interaction ◽  
Ice Nucleation ◽  
Particle Collision ◽  
Charged Droplet ◽  
Particle Collisions ◽  
Ice Nuclei ◽  
Induced Dipole ◽  
Levitated Droplet

Abstract. Heterogeneous nucleation of ice in a supercooled water droplet induced by external contact with a dry aerosol particle has long been known to be more effective than freezing induced by the same nucleus immersed in the droplet. However, the experimental quantification of contact freezing is challenging. Here we report an experimental method to determine the temperature-dependent ice nucleation probability of size-selected aerosol particles. The method is based on the suspension of supercooled charged water droplets in a laminar flow of air containing aerosol particles as contact freezing nuclei. The rate of droplet–particle collisions is calculated numerically with account for Coulomb attraction, drag force and induced dipole interaction between charged droplet and aerosol particles. The calculation is verified by direct counting of aerosol particles collected by a levitated droplet. By repeating the experiment on individual droplets for a sufficient number of times, we are able to reproduce the statistical freezing behavior of a large ensemble of supercooled droplets and measure the average rate of freezing events. The freezing rate is equal to the product of the droplet–particle collision rate and the probability of freezing on a single contact, the latter being a function of temperature, size and composition of the contact ice nuclei. Based on these observations, we show that for the types of particles investigated so far, contact freezing is the dominating freezing mechanism on the timescale of our experiment.

Photochemistry of di-tert-butyl ketone and structural effects on the rate and efficiency of intersystem crossing of aliphatic ketones

1970 ◽  
Vol 92 (23) ◽  
pp. 6974-6976 ◽  
Author(s):  
Nien-Chu. Yang ◽  
Eugene D. Feit ◽  
Man Him. Hui ◽  
Nicholas J. Turro ◽  
J. Christopher. Dalton
Keyword(s):  
Intersystem Crossing ◽  
Structural Effects ◽  
Tert Butyl ◽  
Aliphatic Ketones ◽  
Butyl Ketone
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