Structure-property relations in crystalline L-leucine obtained from calorimetry, X-rays, neutron and Raman scattering

Pedro F. Facanha Filho; Xueshe Jiao; Paulo T. C. Freire; Adenilson O dos Santos; Paul F. Henry; Fabiano Yokaichiya; Ewout Kremner; Heloisa N. Bordallo

doi:10.1039/c0cp02278k

Structure-property relations in crystalline L-leucine obtained from calorimetry, X-rays, neutron and Raman scattering

Pedro F. Facanha Filho, Xueshe Jiao, Paulo T. C. Freire, Adenilson O dos Santos, Paul F. Henry, Fabiano Yokaichiya, Ewout Kremner, Heloisa N. Bordallo

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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 CO ₂ 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 (T₂). 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 T₁ and T₂, as well as with the already reported phase transition at T₃ = 353 K. Through the analysis of the Raman modes, the new structural arrangement observed below T₁ was related to conformational modifications of the CH and CH ₃ groups, while the behavior of the N-H stretching vibration, ν(NH₃), gave insight into the intermolecular N-H...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.

Original language	English
Journal	Physical Chemistry Chemical Physics
Volume	13
Issue number	14
Pages (from-to)	6576-6583
ISSN	1463-9076
DOIs	https://doi.org/10.1039/c0cp02278k
Publication status	Published - 14 Apr 2011
Externally published	Yes

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@article{bef56a5a9e2c4c8e945ad3477564b84b,

title = "Structure-property relations in crystalline L-leucine obtained from calorimetry, X-rays, neutron and Raman scattering",

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 CO 2 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 (T2). 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 T1 and T2, as well as with the already reported phase transition at T3 = 353 K. Through the analysis of the Raman modes, the new structural arrangement observed below T1 was related to conformational modifications of the CH and CH 3 groups, while the behavior of the N-H stretching vibration, ν(NH3), gave insight into the intermolecular N-H...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.",

author = "{Facanha Filho}, {Pedro F.} and Xueshe Jiao and Freire, {Paulo T. C.} and {dos Santos}, {Adenilson O} and Henry, {Paul F.} and Fabiano Yokaichiya and Ewout Kremner and Bordallo, {Heloisa N.}",

year = "2011",

month = apr,

day = "14",

doi = "10.1039/c0cp02278k",

language = "English",

volume = "13",

pages = "6576--6583 ",

journal = "Physical Chemistry Chemical Physics",

issn = "1463-9076",

publisher = "Royal Society of Chemistry",

number = "14",

}

TY - JOUR

T1 - Structure-property relations in crystalline L-leucine obtained from calorimetry, X-rays, neutron and Raman scattering

AU - Facanha Filho, Pedro F.

AU - Jiao, Xueshe

AU - Freire, Paulo T. C.

AU - dos Santos, Adenilson O

AU - Henry, Paul F.

AU - Yokaichiya, Fabiano

AU - Kremner, Ewout

AU - Bordallo, Heloisa N.

PY - 2011/4/14

Y1 - 2011/4/14

N2 - 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 CO 2 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 (T2). 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 T1 and T2, as well as with the already reported phase transition at T3 = 353 K. Through the analysis of the Raman modes, the new structural arrangement observed below T1 was related to conformational modifications of the CH and CH 3 groups, while the behavior of the N-H stretching vibration, ν(NH3), gave insight into the intermolecular N-H...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.

AB - 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 CO 2 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 (T2). 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 T1 and T2, as well as with the already reported phase transition at T3 = 353 K. Through the analysis of the Raman modes, the new structural arrangement observed below T1 was related to conformational modifications of the CH and CH 3 groups, while the behavior of the N-H stretching vibration, ν(NH3), gave insight into the intermolecular N-H...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.

U2 - 10.1039/c0cp02278k

DO - 10.1039/c0cp02278k

M3 - Journal article

SN - 1463-9076

VL - 13

SP - 6576

EP - 6583

JO - Physical Chemistry Chemical Physics

JF - Physical Chemistry Chemical Physics

IS - 14

ER -

Structure-property relations in crystalline L-leucine obtained from calorimetry, X-rays, neutron and Raman scattering

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