%0 Journal Article %1 WOS:000288678900020 %A Filho, Pedro F Facanha %A Jiao, Xueshe %A Freire, Paulo T C %A Jr., Jose A Lima %A dos Santos, Adenilson O %A Henry, Paul F %A Yokaichiya, Fabiano %A Kremner, Ewout %A Bordallo, Heloisa N %C THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND %D 2011 %I ROYAL SOC CHEMISTRY %J PHYSICAL CHEMISTRY CHEMICAL PHYSICS %K imported %N 14 %P 6576-6583 %R 10.1039/c0cp02278k %T Structure-property relations in crystalline L-leucine obtained from calorimetry, X-rays, neutron and Raman scattering %V 13 %X We have studied the amino acid L-leucine (LEU) using inelastic neutron scattering, X-rays and neutron diffraction, calorimetry and Raman scattering as a function of temperature, focusing on the relationship between the local dynamics of the NH3, CH3, CH2 and CO2 moieties and the molecular structure of LEU. Calorimetric and diffraction data evidenced two novel phase transitions at about 150 K (T-1) and 275 K (T-2). The dynamical susceptibility function, obtained from the inelastic neutron scattering results, shows a re-distribution of the intensity of the vibrational bands that can be directly correlated with the phase transitions observed at T-1 and T-2, as well as with the already reported phase transition at T-3 - 353 K. Through the analysis of the Raman modes, the new structural arrangement observed below T-1 was related to conformational modifications of the CH and CH3 groups, while the behavior of the N-H stretching vibration, nu(NH3), gave insight into the intermolecular N H center dot center dot center dot O interactions. The observation of changes in the translational symmetry in the crystalline lattice, as well as anharmonic dynamics, allows for localized motions in LEU.

@article{WOS:000288678900020, abstract = {We have studied the amino acid L-leucine (LEU) using inelastic neutron scattering, X-rays and neutron diffraction, calorimetry and Raman scattering as a function of temperature, focusing on the relationship between the local dynamics of the NH3, CH3, CH2 and CO2 moieties and the molecular structure of LEU. Calorimetric and diffraction data evidenced two novel phase transitions at about 150 K (T-1) and 275 K (T-2). The dynamical susceptibility function, obtained from the inelastic neutron scattering results, shows a re-distribution of the intensity of the vibrational bands that can be directly correlated with the phase transitions observed at T-1 and T-2, as well as with the already reported phase transition at T-3 - 353 K. Through the analysis of the Raman modes, the new structural arrangement observed below T-1 was related to conformational modifications of the CH and CH3 groups, while the behavior of the N-H stretching vibration, nu(NH3), gave insight into the intermolecular N H center dot center dot center dot O interactions. The observation of changes in the translational symmetry in the crystalline lattice, as well as anharmonic dynamics, allows for localized motions in LEU.}, added-at = {2022-05-23T20:00:14.000+0200}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, author = {Filho, Pedro F Facanha and Jiao, Xueshe and Freire, Paulo T C and Jr., Jose A Lima and dos Santos, Adenilson O and Henry, Paul F and Yokaichiya, Fabiano and Kremner, Ewout and Bordallo, Heloisa N}, biburl = {https://www.bibsonomy.org/bibtex/28251a3f4981ea459ee5ecd51fe4ea7ea/ppgfis_ufc_br}, doi = {10.1039/c0cp02278k}, interhash = {0c42bd82c59c407d3dbd3a3455d881be}, intrahash = {8251a3f4981ea459ee5ecd51fe4ea7ea}, issn = {1463-9076}, journal = {PHYSICAL CHEMISTRY CHEMICAL PHYSICS}, keywords = {imported}, number = 14, pages = {6576-6583}, publisher = {ROYAL SOC CHEMISTRY}, pubstate = {published}, timestamp = {2022-05-23T20:00:14.000+0200}, title = {Structure-property relations in crystalline L-leucine obtained from calorimetry, X-rays, neutron and Raman scattering}, tppubtype = {article}, volume = 13, year = 2011 }