scholarly journals Barrier to Rotation about Sulfur-Sulfur Bonds in Homocyclic Sulfur Molecules

1983 ◽  
Vol 38 (5) ◽  
pp. 543-545 ◽  
Author(s):  
Ralf Steudel
Keyword(s):  
Enthalpy Of Formation ◽  
Bond Distance ◽  
Torsional Angles ◽  
The Enthalpy Of Formation

AbstractIt is shown that the distances (d) of the 19 longest bonds in 9 homocyclic sulfur rings of type Sn (n = 6-20) depend on the torsional angles (τ) which vary between 0° and 140°. The function d = f(τ) is smallest for τ = 90-100° and largest for τ = 0°; the corresponding bond distance variation amounts to 13 pm or 6%. The height of the torsional cis-barrier is estimated from the enthalpy of formation of gaseous S7 as equal to or smaller than 24 kJ/mol.

Thermochemistry of Organic and Heteroorganic Species. Part IX. Photoionization Studies of Isomerization and Fragmentation of Polysubstituted Cyclopropenes: Phenyl-Substituted Cyclopropenes

2000 ◽  
Vol 6 (1) ◽  
pp. 53-64 ◽  
Author(s):  
V.V. Takhistov ◽  
I.N. Domnin ◽  
D.A. Ponomarev
Keyword(s):  
Mass Spectrometry ◽  
Enthalpy Of Formation ◽  
Good Alternative ◽  
Enthalpies Of Formation ◽  
Isodesmic Reactions ◽  
Ion Structure ◽  
Photoionization Mass Spectrometry ◽  
General Methodology ◽  
Fragment Ions ◽  
The Enthalpy Of Formation

Ionization and appearance energies of some fragment ions from 1,2,3-trimethy1-3-phenyl-, 3-methyl-1,2,3-triphenyl-, 1,2-diphenyl-3-methoxycarbonyl-, 1,2,3-triphenyl-3-methoxycarbonyl- and 1,3,3-triphenyl-2-methoxycarbonyl-cyclopropenes were measured by photoionization mass spectrometry. It was shown that in none of these compounds did the fragment ions possess the expected stable substituted cyclopropenium ion structure. Accordingly, possible schemes of molecular ion isomerization are given. The enthalpies of formation of nearly 50 substituted cyclopropenium ions, and ions of related structure, were estimated using series of isodesmic reactions. This publication, together with the previous works of the authors in this Journal, demonstrates the general methodology for estimation of the enthalpy of formation for even-electron ions. It is suggested that the present methodology can provide a good alternative to other estimation or computation procedures applied to the thermochemistry of ions.

Measurement of the enthalpy of formation of an iron pico-hydride and of its main properties

2017 ◽  
Vol 31 (25) ◽  
pp. 1745007
Author(s):  
Jacques Dufour ◽  
Xavier Dufour ◽  
Fabienne Dioury ◽  
Jenny D. Vinko
Keyword(s):  
Enthalpy Of Formation ◽  
Electric Dipole ◽  
Atomic System ◽  
Binding Energies ◽  
Iron Nucleus ◽  
Atomic Size ◽  
The Standard Model ◽  
Typical Distances ◽  
Species Being ◽  
The Enthalpy Of Formation

Chemical reactions result from the outside shell electrons of the reacting species being shared in various types of combinations. Typical distances involved are tenths of nm, resulting in binding energies typically in the order of hundreds of kJ/mole (eV/atom). The synthesis of a novel “atomic system” formed from Iron and di-Hydrogen has been achieved. The measured enthalpy of formation is some 40 MJ/moleFe and the distance between the hydrogen proton and the iron nucleus is some 8 pm, hence the proposed name: Iron Pico-Hydride. This compound is a permanent electric dipole of atomic size. Pico-Hydrides could, thus, play a significant role in HT superconductivity and in super-capacitors. The synthesis is compatible with the standard model.

The Enthalpy of Formation and C−H Bond Enthalpy of Hydrofullerene C60H36

2002 ◽  
Vol 106 (9) ◽  
pp. 2127-2130 ◽  
Author(s):  
Svetlana M. Pimenova ◽  
Svetlana V. Melkhanova ◽  
Victor P. Kolesov ◽  
Anatolii S. Lobach
Keyword(s):  
Enthalpy Of Formation ◽  
The Enthalpy Of Formation

The enthalpy of formation of benzoyl chloride

1972 ◽  
Vol 4 (5) ◽  
pp. 731-737 ◽  
Author(s):  
J.V Davies ◽  
B.K Dunning ◽  
H.O Pritchard
Keyword(s):  
Enthalpy Of Formation ◽  
Benzoyl Chloride ◽  
The Enthalpy Of Formation
Sign in / Sign up

Export Citation Format

Share Document