Hydrogen bonding in solid alcohols

Abinitio studies on hydrogen bonded chains. V. The structure of infinite chains of methanol and water molecules

“…however, that the chain structure persists in all solid phases of methanol. Detailed analysis of vibrational spectra of solid methanol substantiated the structural results (9)(10)(11)(12)(13)(14).…”

Vibronic model for H/D isotopic “self-organization” effects in hydrogen bond cyclic trimeric systems: 4-Bromopyrazole crystal IR spectra

“…However, the latest studies on the residual m X-H bands have suggested that a new kind of H/D isotopic effects for hydrogen bond systems existed, namely the so called isotopic ''self-organization'' effects [15][16][17][18][19]. For the first time these effects were revealed for cyclic, centrosymmetric dimeric systems of hydrogen bonds, for which the shapes of residual m X-H bands remained almost invariant, when the deuterium substitution rate increased; such behavior remained in contrast with predictions of the most recent advanced theoretical models [5][6][7][8][9][10][11][12][13]20,21].…”

“…3-8 kcal/mol, these co-operative interaction effects determine ca. 10-15% of the dimer hydrogen bond energy [15,20]. This correction is comparable with the magnitude of the contribution to the total hydrogen bond energy, introduced for instance by dispersion forces, or by the charge transfer mechanisms [38].…”

“…Most probably, when a cycle dimension grows, some essential restrictions in the H/ D isotopic ''self-organization'' mechanisms should appear, as only some of the chain systems exhibited these effects in their IR spectra [22,24]. In the spectra of another group of the chain systems these effects were absent [20,21,29]. Therefore our aim was also to check experimentally, if the H/D isotopic ''self-organization'' effects appeared in the IR spectra of the trimer hydrogen-bonded model, in the way predicted by the proposed theoretical model.…”

Calculations on vibrational properties of H-bonded OH groups, as a function of H-bond geometry

“…This Davydov splitting is proportional to I/R3 and so will be reduced if I is small and R is large. For crystals of primary alcohols, with R 1 3 A, splittings of up to 90 cm-' have been reported [25]. These alcohols are strongly hydrogen bonded, thus their I may be expected to be of the order I = 0.4 a.u.…”