Analysis of the H-:hridge in Carboxyllic Acids in Terms of Stabilization Energy Derived from Bond Lengths. Non-Hammett Properties of p-Substituted Benzoic Acids in the Crystalline State
نویسندگان
چکیده
Harmonic oscillator stabilization energy (HOSE) is defined as the negative value of deformation energy necessary to transform a molecule from its natural geometry to its Kekule structure with purely single and double bonds. It was found that HOSE-values for dimers of carboxylic acids with centrosymmetric hydrogen bonds are well related (correlation coeff. r = 0.972) to the Ro . . . o distances for 19 species for which measurements were carried out in both the crystalline and gaseous states. Stability of many other Jt-systems, e. g. aromatic and unsaturated hydrocarbons, polymethine systems (e.g. cyanine dyes), EDA-complexes, quinoid systems, etc. are successfully described in terms of HOSE-values.
منابع مشابه
Infrared and Raman Studies of Carbonyl Group Frequencies of p-Substituted Benzoic Acids in the Crystalline State
It was found 1 that Ro ... 0 distances in cyclic dimers of p-substituted benzoic acids in the crystalline state do not follow the Hammett rule. The Ro ... 0 values often serve as an approximate measure of hydrogen bond strength.2 Since substituent constants op and R0 ... 0 express the Bronsted and the Lewis acidity of the carboxylic group in solution and in the crystalline state, respectively, ...
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