ISSN:
0947-3440
Keywords:
Enthalpies of formation
;
Geminal substituents, energetic interaction of
;
Bond cleavage, C—C, kinetics of
;
Radicals, stability of
;
Increments, thermochemical
;
Bond strength, substituent effects on
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Substituent Effects on the CC Bond Strength, 16. - Thermal Stability and Enthalpies of Formation of β-Dicarbonyl Compounds. - Stabilisation Enthalpies of α,α′-Diketoalkyl RadicalsThe geminal interactions of the two carbonyl groups in seven β-diketones of the type 8-9 and 11-13 were estimated from their enthalpies of formation, which were deduced from their heats of combustion and enthalpies of vaporization. The radical stabilisation enthalpies RSE of the α,α′-diketoalkyl radicals 9-13 were obtained from the enthalpies of activation ΔH≠ of thermal CC bond cleavage of eight model compounds of the type 9-13 by their comparison with ΔH≠ of comparable hydrocarbons of similar strain. For non-cyclic α,α′-diacyl-alkyl radicals and six-membered cyclic ones RSE = 54.8 ± 1.3 kJ mol-1 was determined, which indicates an additive stabilisation by two carbonyl groups.
Additional Material:
11 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.199519950108
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