Badger-Bauer

Figure 3.2 Illustration of the Badger-Bauer relationships for HCl" base where the base is a sesries of 4-substituted pyridines. Data - calculated at MP2/6-31 +G(d,p) level. The dashed line represents the magnification of the intensity in the dimer, relative to the moment. AE refers to the electronic contribution to the binding energy.

Rao, C. N. R., Dwivedi, P. C., Ratajczak, H., and Orville-Thomas, W. J., Relation between O—H stretching frequency and hydrogen bond energy Re-examination of the Badger-Bauer rule, J. Chem. Soc., Faraday Trans. 71, 955-966 (1975). 

It should be noted that the Av(OH) and AH values vary in opposing directions. This apparent contradiction to the Badger-Bauer rule , also found in the intermolecular association of phenols with haloalkanes , is another example of the family dependence of this rule. For 2-fluorophenol, 2,6-difluorophenol and tetrafluorohydroquinone, gas-phase electron diffraction studies indicate the existence of a weak IHB " ". The lengths of the hydrogen bonds H- -F (2.13, 2.05 and 2.02 A, respectively) are 80% shorter than the sum of the van der Waals radii of the hydrogen and fluorine atoms. 

Badger-Bauer mle 555 Badger-type relations 133 Baeyer-ViUiger oxidation 424, 647, 701, 799 Baker-Venkataraman rearrangement 740, 743, 778... 

The position of hydrophilic molecules in the series of H-bond acceptors can be determined spectroscopically by the Badger-Bauer rule from Av of the water bands (12.U3,UU). We obtained the series acetonitrile < dioxane dimethylsiilfoxide < pyridine < triethylamine.A comparison with ice spectra gives acceptor strength of HgO between pyridine and triethylamine ( 1 ). 

Different attempts to use spectral features as a measure of hydrogen bonding strength have always been popular throughout the development of this field of science. The simple Badger-Bauer rule (Eq. 6) continued to be considered valid even after the non-linearity of the function -AH = f(Av) was demonstrated [2,34]. 

Figure 12.16 Badger-Bauer rule Linear relationship between H-bond strength and magnitude of red-shifting in O-H stretching frequency. (Source Bhatta 2014 (31). Reproduced with permission of World Scientific...

Bhatta, R. S., Iyer, P. P., Dhinojwala, A., and Tsige, M. (2014). A brief review of Badger-Bauer rule and its validation from a first-principles approach. Mod. Phys. Lett. B, 28(29), 1430014. 

The Badger-Bauer rule states that there is a linear relationship (in solution) between the shift Av(A-H) and AH, the enthalpy of H-bond formation, but it was formulated originally from early and somewhat limited data. More comprehensive work has since shown that there are deviations from linearity, most... 

Rao CNR, Dwivedi PC, Ratajczak H and Orville-Thomas WJ (1975) Relation between 0-H stretching frequency and hydrogen bond energy re-examination of the Badger-Bauer rule. Journal of the Chemical Society, Faraday Transactions 1171 955-966. 

These positions actually do not violate the empirical Badger-Bauer rule... 

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