The manifestation of hydrogen bonding in the IR spectra of dl-threitol and erythritol (300–20 K)

Low-temperature infrared spectra and hydrogen bonding in polycrystalline dl-serine and deuterated derivatives

“…One of the relevant conclusions from our previous studies was the unequivocal demonstration of the ubiquitous existence of non-negligible H-bonding disorder in crystalline state that cannot be investigated using standard structural methods (e.g., X-ray and neutron diffraction) because of the low sensitivity of these methods to short-range interactions [3][4][5][6][7]12,13]. This fact stresses the relevance of using spectroscopic techniques to investigate the details of H-bonding networks in the crystalline phase.…”

“…This expression was obtained taking into consideration data collected for a considerable number of H-bonded systems, including crystalline carbohydrates [12,13], nucleobases (cytosine [4], uracil and thymine [5]), nucleosides (cytidine [6], adenosine and uridine [7]) and several amino acids (glycine, alanine, glutamine, hystidine, tyrosine and threonine [2,8]). …”

“…It is also possible to estimate thermodynamic properties related with hydrogen bonds from the spectroscopic data using the empirical correlations between the H-bond energy and (i) the blue shift of the n 4 mode bands {ÀDH ¼ 0:67Dn 2 4 , where Dn 2 4 10 À4 ½ðn 4 Þ 2 À ðn 0 4 Þ 2 ; n 4 in cm À1 [12,41], and DH is expressed in kJ mol À1 }or (ii) the red-shift of the stretching vibration of the H-bond donor group {(DH/kJ mol À1 ) 2 = 1.92 (Dn 1 cm À1 À 40) [40]}.…”

“…At low temperature (<30 K), the bandwidth associated with these decoupled vibrations changes typically from hundreds to tens of wavenumbers and, as a result, the spectral resolution of the IR spectra improves significantly, allowing the observation of proton-related bands ascribable to specific Hbonds in the crystal. This approach was previously applied successfully to study of the H-bonding structure in crystalline carbohydrates [12,13], nucleobases (cytosine [4], uracil and thymine [5]), nucleosides (cytidine [6], adenosine and uridine [7]) and several amino acids (glycine, alanine, glutamine, histidine, tyrosine and threonine [2,8]), and led to the establishment of very general correlations between the frequency shifts of the proton vibrations upon hydrogen-bond formation and the corresponding H-bond lengths and energies [1,3,8].…”

Spontaneous self-association of adenine and uracil in polycrystals from low temperature FTIR spectra in the range below 1000cm−1

“…A very important property exhibited by the bands due to the out of plane NH modes is that, in contrast to those due to the NH stretching vibrations, they do not change their molar integral intensity with the H-bond energy and thus remain narrow and well resolved, independently of the strength of the H-bond interaction [7]. This spectral region can then be used, for example, for a direct quantitative estimation of the relative abundance of different H-bonds in a given crystal [8,9]. On the other hand, like in the case of the NH stretching region, the peak positions of the bands due to out of plane NH bending modes are sensitive to the H-bond energy (and, consequently, to the H-bond geometry) and can be used to estimate this property on the basis of simple empirical quantitative relationships [7,[10][11][12].…”