114. Studies in hydrogen-bond formation. Part IV. The hydrogen-bonding properties of water in non-aqueous solution and of alcohols, aldehydes, carbohydrates, ketones, phenols, and quinones in aqueous and non-aqueous solutions

Abstract

By application of the refractive-index method of detecting complex formation in solution to over one hundred systems in various solvents the following conclusions are reached. The hydroxyl group in alcohols is monofunctional in hydrogen-bond formation and when present on vicinal carbon atoms in an aliphatic chain it forms weak five-membered chelate rings ; consequently only one end-group in, e.g., glycerol or mannitol, is normally available for intermolecular bonding. I n aldehydes a variety of reactions demonstrate that the aldehyde group probably forms inter-and intraiiiolecular bonds through its hydrogen atom.In aqueous solutions of carbohydrates the open-chain form of glucose or cellobiose, in presence of certain other solutes, such as pyridine or amines, is stabilised by hydrogen-bond interaction of the aldehyde group ; the hydroxygroups are inactive because of solvation by water, though they are active in ethylene glycol solution. In aqueous solutions the hydroxy-groups are less reactive in the ring than in the open-chain forms of the simple carbohydrates and in the ring forms they do not combine with other solutes, even phenol. The bearing of these facts on the adsorption behaviour of cellulose is discussed.The keto-group of ketones behaves bifunctionally and the quinone oxygen atom of quinones monofunctionally ; ketones do not however form intermolecular complexes in benzene, ether, or water solutions. In nonaqueous solvents water appears to act either bifunctionally, probably by cross-linking, or monofunctionally in forming hydrogen-bond complexes with second solutes.

Mechanisms of retention of organic volatiles in freeze‐dried systems *

“…analysis; the results are shown in Table 1. Water is known to interact strongly vith free hydroxyl groups of carbohydrates (Arshid, Giles & Jain, 1956), and it is this nteraction of water with free hydroxyl groups of the dried material that is measured ~y B.E.T. analysis.…”

Nature and strength of C–H⋯O interactions involving formyl hydrogen atoms: computational and experimental studies of small aldehydes

“…Several spectroscopic and crystallographic studies support the existence of such an association based upon the shifts observed in IR and NMR spectra of aldehydes. [4][5][6][7][8][9][10][11][12] Weber et al investigated the role of the formyl C-HÁ Á ÁO hydrogen bond in molecular recognition based upon ab initio studies of formic acid and formamide dimers. 13 These workers estimated that the C-HÁ Á ÁO interaction in the formic acidformamide cyclic dimer contributes about 15-20 kJ mol À1 to the stability of the complex.…”

Characterization of non-covalent contacts in mono- and di-halo substituted acetaldehydes: probing the substitution effects of electron donating and withdrawing groups

“…Several spectroscopic and crystallographic studies have reported the existence of the formyl C–H⋯O hydrogen bond based on the shifts observed in IR and NMR spectra of aldehydes. 20 Moorthy, Venugopalan and co-workers have explored the role of formyl C–H⋯O interactions in defining crystal packing through their work on the formyl C–H⋯O interactions in the crystal structures of coumarins and aromatic aldehydes. 21 Osman et al 22 reported the relative stability of the eclipsed and bisected acetaldehydes at the Møller–Plesset second order perturbation level of theory (MP2) employing aug-cc-pVDZ basis sets.…”