Intramolecular hydrogen bonding in 2-hydroxyalkylpyridines and 2-hydroxyalkylpiperidines

Proton NMR and IR study of self‐association in pyridylalkanols: open or cyclic dimers? higher polymers?

“…2-(X-Pyridyl)propan-2-ols and (X-pyridyl)alkanols About 35 years ago a series of (2-pyridyl)alkanols, 1a-c, was investigated by IR 41 and NMR 39 spectroscopies. In the first part of this study we seek, by means of IR spectroscopy, qualitative information concerning both intra-and intermolecular hydrogen bonding in 1a-c and some 3-and 4-pyridyl derivatives, 2a, 2c, and 3.…”

“…Previous work appears to be limited to three studies. [39][40][41] The NMR chemical shift of the OH hydrogen in (2-pyridyl)alkanols in chloroform increases with concentration, indicating intermolecular hydrogen bonding, despite the proximity of the OH group and the nitrogen atom. 39 In contrast, (2-pyridyl)di(1adamantyl)methanol was isolated as the syn rotamer with an intramolecular hydrogen bond.…”

“…40 Intramolecular hydrogen bonding in (2-pyridyl)alkanols was also investigated by IR spectroscopy. 41 The aim of this work is to determine as far as possible by NMR and IR spectroscopies the nature and degree of the apparent association in (2-pyridyl)alkanols and to extend this study to 3-and 4-substituted derivatives. Steric effects on association will be investigated by replacing the CH 2 hydrogens of the (X-pyridyl)methanols by, firstly, methyl groups [2-(X-pyridyl)propan-2-ols] and then by tert-butyls [3-(X-pyridyl)-2,2,4,4-tetramethylpentan-3-ols].…”

Photoelectron studies on intramolecularly hydrogen-bonded systems. I. The photoelectron spectra of cis- and trans-2-aminocyclopentanol, and cis- and trans-2-(N,N-dimethylamino)cyclopentanol

“…Certainly the data of Table 2 do not contradict these observations. On the other hand, one might expect that increasing the basicity of the nitrogen by substitution (6) should increase the hydrogen bond strength (12). If it is assunled that the controversial BadgerBauer rule (14) holds, which states that AV is indicative of the enthalpy of the hydrogen-bond, then we would expect the ir data for 10 and 16 might reflect the different hydrogen-bond strengths.…”

“…Within each series, the t m s isomer shows AV ('free' OH -'bonded' OH) to be larger than the cis isomer. It has been observed that 1,2-and 1,3-amino alcohols (12) and diols (13) show larger AV values for interlnolecular than intranlilecular hydrogen-bonding pres~unably due to geometric restraints in the latter which prevent optimum interaction. Certainly the data of Table 2 do not contradict these observations.…”