Bond energies carbon-chlorine

Keyes and Marshall[325] found that CI2 adsorption on degassed activated carbon is exothermic. Its initial heat amounts to 31,9 kcal mol and drops to 24.6 kcal mol with increasing concentration of adsorbed chlorine. This corresponds to an energy of 44 kcal mol for the C-Cl adsorption bond (with a subsequent decrease to 41 kcal mol ), which is considerably lower than typical values of the C-Cl bond energy in chlorine-containing organic compounds 70 kcal mol [304]). 

Carbon-Hydrogen and Carbon-Chlorine Bond Dissociation Energies of Selected Compounds... 

The last example represents a fairly rare elimination of hydrogen fluoride in preference to hydrogen chloride, a reaction that deserves a more detailed discussion A comparison of bond dissociation energies of carbon-halogen bonds shows that the carbon-fluorine bond is much stronger than the carbon-chlorine, carbon-bromine, and carbon-iodme bonds 108-116, 83 5, 70, and 56 kcal/mol, respec-... 

C06-0107. Phosgene (CI2 C I O) is a highiy toxic gas that was used for chemical warfare during World War I. Use the bond energies in Table 6 2 to estimate the energy change that occurs when carbon monoxide and chlorine combine to make phosgene. C I 0(g) + Cl2(g) CI2 C I 0(g)... 

Inspection of the two sets of chair structures reveals that in one compound the all-equatorial conformer is overwhelmingly favored. In the other compound both chair structures have comparable energies so both will be populated significantly. In the all-equatorial isomer, the carbon-chlorine bond dipole moments reinforce one another leading to a large molecular moment. In the other compound the chlorines are both equatorial part of the time but part of the time they are trans diaxial where the carbon-chlorine bond dipole moments tend to cancel one another. Thus the average dipole moment of these two conformations will be less than the first compound, which exists virtually completely in the all-equatorial conformer. 

Of this group only benzyl chloride is not an aryl halide its halogen is not attached to the aromatic ring but to an. v/r -hybridized carbon. Benzyl chloride has the weakest carbon-halogen bond, its measured carbon-chlorine bond dissociation energy being only 293 kJ/mol (70 kcal/mol). Homolytic cleavage of this bond produces a resonance-stabilized benzyl radical. 

A survey and carbon Is spectrum from untreated white pine is shown in Figure 36. Survey spectra and chlorine 2p as well as carbon Is spectra are shown in Figure 37 taken from white pine treated with hydrogen peroxide, HCL, and acetic acid with heating. This oxidative treatment has oxidized carbon as evidenced by shoulders in the C Is spectra at higher binding energies and introduced carbon chlorine bonds on the surface as evidenced by the chlorine 2p line around 200 eV. 

Branching should incorporate weaker tertiary bonds in PVC, either carbon-hydrogen or carbon-chlorine. Secondary and tertiary C-H bonds have bond dissociation energies of 94 and 90 Kcal/mole respectively. A tertiary carbon-chlorine bond may require even more energy for homolytic cleavage than a secondary one, i.e. 75 versus 73 Kcal/mole (20). Cleavage of the branch... 

In making a covalent bond between carbon and chlorine from the 2px orbital on carbon and the 3px orbital on chlorine, we have an interaction (Fig. 1.45) between orbitals of unequal energy (-10.7 eV for C and -13.7 eV for Cl, from Table 1.1). The interaction diagram could equally have been drawn using sp3 hybrids on... 

If the addition stage is rate-limiting, which is usually the case, polarity of the bond to carbon is probably the most important factor governing the activation energy required, since fluorine is sometimes displaced more easily than chlorine or the other halogens. For example, benzoyl fluoride reacts more readily with hydroxide than the corresponding... 

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