FIR spectra of amino acids and related molecules

Husain, Shad; Hasted, J. B.; Rosen, D.; Nicol, Elisabeth A.; Birch, J.R.

doi:10.1016/0020-0891(84)90070-8

Cited by 18 publications

(7 citation statements)

References 8 publications

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“…groups) are frozen in different temperature ranges on cooling or at different pressures on squeezing. Different experimental techniques (IR and Raman spectroscopy, − ,− ,,,− ,− ,− picosecond coherent Raman scattering (ps CARS), , terahertz spectroscopy, NMR, − , electron spin echo, pulsed ESR spectroscopy, adiabatic calorimetry, ,,,,,, X-ray diffraction, ,,,,,,− IINS 43,59,82 ) are sensitive to the motions with different relaxation times and can, therefore, detect selectively different types of disorder in the crystals of amino acids. This often leads to confusion and seeming discrepancies in the conclusions on the occurrence of a phase transition based on using different experimental techniques.…”

Section: Discussionmentioning

confidence: 99%

Difference in the Dynamic Properties of Chiral and Racemic Crystals of Serine Studied by Raman Spectroscopy at 3−295 K

Boldyreva

2007

J. Phys. Chem. B

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Single-crystal polarized Raman spectra (60-4000 cm(-1) at 3 < or = T < or = 295 K) were measured for chiral L- and racemic DL-serine, alpha-amino-beta-hydroxypropionic acid, (NH3)+CH(CH2OH)(COO)-. The Raman spectra of dl-serine do not show any striking changes with temperature or on storage. In contrast to that, the dynamical properties of L-serine change at about 140 K. These changes can be interpreted as the reorientation of the side chain -CH2OH fragments of the zwitterions with respect to the backbone C-C bonds, resulting in the positional disorder of the O-H...O intermolecular H-bonds. The redistribution in the intensities of the Raman spectra of the crystals of L-serine stored for a long time (about a year) indicates the changes in the orientation of the molecular fragments in the direction normal to the axes of the head-to-tail chains. The difference in the thermodynamic functions of L- and DL-serine reported previously [Drebushchak, V. A.; Kovalevskaya, Yu. A.; Paukov, I. E.; Boldyreva, E. V. J. Therm. Anal. Calorim. 2007, 89 (2), 649-654] is explained by the difference in the spectra of external vibrations of the crystals.

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Section: Discussionmentioning

confidence: 99%

Difference in the Dynamic Properties of Chiral and Racemic Crystals of Serine Studied by Raman Spectroscopy at 3−295 K

Boldyreva

2007

J. Phys. Chem. B

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“…The shoulder at 300 cm-' is due to the torsional vibration of OH33'. The torsion of C-C-C could also cause the formation of a broad band centered around 220 cm-' 33). It is also interesting to observe that in Although other authors have reported some portions of this spectroscopic characterizationg* lM6), this is the only known complete description throughout the entire IR region.…”

Section: Ir Measurementsmentioning

confidence: 94%

Characterization of chitosan and rare‐earth‐metal‐ion doped chitosan films

Jiang

Liang

Grant

et al. 1997

Macro Chemistry & Physics

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A systematic study has been made on the influence of doped rare-earth metal ions (E? and Nd3+) on the molecular interaction present in thin films fabricated from chitosan-acetic acid solutions (chitosan/HAc). FT-IR spectroscopy (including NIR, MIR and FIR) coupled with X-ray photoelectron spectroscopy (XPS) indicate a weak complexation between the metal ions and amine groups of chitosan. Specifically, the FIR spectra show broad bands near 550, 480 and 250 cm-' for the doped films suggestive of metal ion-ligand vibrations. XPS indicates multiple chemical states of N with an increased percentage of a higher binding energy state nitrogen caused by a weak interaction with the doped metal ions. Slight differences in microroughness between the doped and undoped films as observed by X-ray reflectometry may also be related to the doping. The NIR and MIR spectra do not show any significant changes for all the doped and undoped films, implying that the basic molecular conformation of chitosan is not changed by the weak complexation.

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“…The motions similar to the relaxation of excited torsional oscillations to lower frequency modes, which are observed in the crystalline amino acids at low temperatures, dominate the atomic mean square displacements in proteins at ambient temperature and have functional significance, e.g., facilitating migration of small ligands through biopolymers by structural fluctuations, opening the gateway to the ligand binding sites, and altering the ligand binding barrier . The low-frequency range of vibrational spectra of glycine (presumably, in all the cases of the α-form, although not always specified explicitly) was studied by ps CARS , far-infrared, – Raman, , and, recently, by terahertz spectroscopy (the latter for α- and the γ-polymorphs at 300 K) in all the cases, either at room temperature or at a single low temperature only.…”

Section: Introductionmentioning

confidence: 99%

“…Among other spectroscopic techniques, incoherent inelastic neutron scattering (IINS) has several advantages, especially in the low-frequency range, due to the strong incoherent scattering from protons. In fact, scattering by hydrogen is considerably stronger than by any other nucleus and thus dominates the signal if present; thus effects involving the dynamics of hydrogen atoms can definitely be observed. , Up until now, IINS spectra have been reported for several crystalline amino acids. – α-Glycine (C- and D-deuterated isotopomers) was studied by IINS at 20, , 100, and 300 K . In ref , the interaction between water and some amino acids (glycine, l -glutamine, l -threonine, l -cysteine, and l -serine) was studied.…”

Section: Introductionmentioning

confidence: 99%

Structure−Property Relationships in the Crystals of the Smallest Amino Acid: An Incoherent Inelastic Neutron Scattering Study of the Glycine Polymorphs

et al. 2008

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Incoherent inelastic neutron scattering spectra for the three crystalline polymorphs (alpha- P2(1)/n, beta- P2(1), gamma- P3(1)) of glycine (C2H5NO2) at temperatures between 5 and 300 K (using the time-of-flight (ToF) spectrometer NEAT at HMI) and at pressures from ambient up to 1 GPa (using the ToF spectrometer IN6 at the ILL) were measured. Significant differences in the band positions and their relative intensities in the density of states (DoS) were observed for the three polymorphs, which can be related to the different intermolecular interactions. The mean-squared displacement, (T), dependence reveals a change in dynamic properties at about the same temperature (150 K) for all the three forms, which can be related to the reorientation of the NH3 group. Besides, a dynamic transition in beta-glycine at about 230-250 K on cooling was also observed, supporting previously obtained adiabatic calorimetry data. This behavior is similar to that already observed in amorphous solids, on approaching the glass transition temperatures, as well as in biological systems. It suggests the onset of degrees of freedom most likely related to transitions between slightly different conformational orientations. The DoS obtained as a function of pressure has confirmed the stability of the alpha-form with respect to pressure and also depicted a sign of the previously reported reversible beta-beta' glycine phase transition in between 0.6 and 0.8 GPa. Moreover, a remarkable kinetic effect in the pressure-induced phase transition in gamma-glycine was revealed. After the sample was kept at 0.8 GPa for an hour in the neutron beam, an irreversible transition into a high-pressure form (different from the beta'-form) occurred, although previously in X-Ray diffraction and Raman spectroscopy experiments a gamma- to delta-glycine phase transition was observed above 3.5 GPa only.

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FIR spectra of amino acids and related molecules

Cited by 18 publications

References 8 publications

Difference in the Dynamic Properties of Chiral and Racemic Crystals of Serine Studied by Raman Spectroscopy at 3−295 K

Difference in the Dynamic Properties of Chiral and Racemic Crystals of Serine Studied by Raman Spectroscopy at 3−295 K

Characterization of chitosan and rare‐earth‐metal‐ion doped chitosan films

Structure−Property Relationships in the Crystals of the Smallest Amino Acid: An Incoherent Inelastic Neutron Scattering Study of the Glycine Polymorphs

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