Torsional frequencies and enthalpies of intramolecular hydrogen bonds of o-halophenols

Stereospecific Spin–Spin Coupling between Hydroxyl Protons and 19F Nuclei in o-, m- and p-Fluorophenol Derivatives. "Through-space" Interactions via the Hydrogen Bond

“…When Z = H, as in 1, no coupling to H,,' was observed, indicating the predominance of the intramolecular hydrogen bonded form in the equilibrium; this is in agreement with far infrared data which gave enthalpies of formation of the intramolecular hydrogen bond, 0-H...X as lying between 1.44 and 1.62 kcal/mol (36).…”

Gas phase enthalpies of formation of monobromophenols

“…The 2-bromophenol (figure 2) is the most stable isomer, suggesting an effect of stabilization when the bromine atom is in the ortho position of the phenolic ring, as a result of the interaction between the bromine and the hydrogen atom of the hydroxyl group. The formation of a hydrogen bond has been previously reported for 2-bromophenol based on results from Raman spectroscopic and far-infrared experiments [11,12]. Hence, for molecules where the bromine atom and the hydroxyl group are attached in ortho position in the benzene ring, the Cox scheme must be applied with some caution, since the stabilizing interactions between these two substituents are totally neglected.…”

“…Particularly the ortho halophenols have been the subject of numerous experimental [10][11][12][13][14][15][16][17] and theoretical [10,[18][19][20] studies focused on the bond strength, geometry, and stabilization energy induced by hydrogen bonding. Considering 2-bromophenol it has been shown in previous works that its molecular structure is planar, and the most stable conformation is that where the hydroxyl group adopts a cis configuration relatively to the bromine atom in 2-position, yielding the formation of a halogen-hydrogen bond.…”

Information from stereospecific spin–spin couplings about the relative absorptivities of the hydroxyl stretching bands in 2-iodophenol solutions

“…Note, however, that a change in concentration from 1.3 to 0.2mol% in C,H,, entails an upfield shift of only 0.022ppm. Because the dimenzation of Ziodophenol is expected to be largest in C6H,, (17), and because the shift for the dimer would certainly be as large as 7 For personal use only. (17).…”