The Experts below are selected from a list of 90 Experts worldwide ranked by ideXlab platform
Bernard Hennion - One of the best experts on this subject based on the ideXlab platform.
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influence of deuteration on lithium acetate dihydrate studied by inelastic x ray scattering density functional theory thermal expansion elastic and thermodynamic measurements
Dalton Transactions, 2011Co-Authors: Florian Schroder, Eiken Haussuhl, A Bossak, Keith Refson, Björn Winkler, Bernard Hennion, J D Bauer, Victor Milman, M KrischAbstract:The influence of deuteration on the properties of lithium acetate dihydrate has been investigated by thermal expansion measurements, ultrasound spectroscopy and calorimetry. Inelastic X-ray scattering has been employed to investigate if the low temperature structural phase transition can be detected by a change in the vibrational spectrum. Density functional theory, DFT, calculations have been employed to complement the experimental investigations. The thermal expansion coefficients and the specific heat of the Deuterated Compound differ significantly from the protonated form. The differences in the elastic stiffness coefficients are just above the detection limit of the technique employed here. Temperature dependent inelastic X-ray spectroscopic measurements show no significant change of the vibrational spectrum when crossing the transition temperature. The DFT calculations show that the methyl group dynamics are best described in the framework of coupled rotators of opposing methyl groups. One of the coupled rotational modes corresponds to a hindered rotator with a barrier of 15 meV, while the other is a free rotator.
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low temperature structural phase transition in Deuterated and protonated lithium acetate dihydrate
The Journal of Chemical Thermodynamics, 2010Co-Authors: Florian Schroder, Eiken Haussuhl, P T Cong, M Avalosborja, Björn Winkler, Marc Quilichini, B. Wolf, Bernard HennionAbstract:Abstract Heat capacity measurements of protonated lithium acetate dihydrate show a structural phase transition at T = 12 K. This finding is in contrast to earlier work, where it was thought that only the Deuterated Compound undergoes a low temperature structural phase transition. This finding is confirmed by low temperature ultrasound spectroscopy, where the structural phase transition is associated with a velocity decrease of the ultrasonic waves, i.e. with an elastic softening. We compare the thermodynamic properties of the protonated and Deuterated Compounds and discuss two alternatives for the mechanism of the phase transition based on the thermal expansion measurements.
Björn Winkler - One of the best experts on this subject based on the ideXlab platform.
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influence of deuteration on lithium acetate dihydrate studied by inelastic x ray scattering density functional theory thermal expansion elastic and thermodynamic measurements
Dalton Transactions, 2011Co-Authors: Florian Schroder, Eiken Haussuhl, A Bossak, Keith Refson, Björn Winkler, Bernard Hennion, J D Bauer, Victor Milman, M KrischAbstract:The influence of deuteration on the properties of lithium acetate dihydrate has been investigated by thermal expansion measurements, ultrasound spectroscopy and calorimetry. Inelastic X-ray scattering has been employed to investigate if the low temperature structural phase transition can be detected by a change in the vibrational spectrum. Density functional theory, DFT, calculations have been employed to complement the experimental investigations. The thermal expansion coefficients and the specific heat of the Deuterated Compound differ significantly from the protonated form. The differences in the elastic stiffness coefficients are just above the detection limit of the technique employed here. Temperature dependent inelastic X-ray spectroscopic measurements show no significant change of the vibrational spectrum when crossing the transition temperature. The DFT calculations show that the methyl group dynamics are best described in the framework of coupled rotators of opposing methyl groups. One of the coupled rotational modes corresponds to a hindered rotator with a barrier of 15 meV, while the other is a free rotator.
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low temperature structural phase transition in Deuterated and protonated lithium acetate dihydrate
The Journal of Chemical Thermodynamics, 2010Co-Authors: Florian Schroder, Eiken Haussuhl, P T Cong, M Avalosborja, Björn Winkler, Marc Quilichini, B. Wolf, Bernard HennionAbstract:Abstract Heat capacity measurements of protonated lithium acetate dihydrate show a structural phase transition at T = 12 K. This finding is in contrast to earlier work, where it was thought that only the Deuterated Compound undergoes a low temperature structural phase transition. This finding is confirmed by low temperature ultrasound spectroscopy, where the structural phase transition is associated with a velocity decrease of the ultrasonic waves, i.e. with an elastic softening. We compare the thermodynamic properties of the protonated and Deuterated Compounds and discuss two alternatives for the mechanism of the phase transition based on the thermal expansion measurements.
Magnus Sandström - One of the best experts on this subject based on the ideXlab platform.
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Vibrational spectroscopic force field studies of dimethyl sulfoxide and hexakis(dimethyl sulfoxide)scandium(III) iodide, and crystal and solution structure of the hexakis(dimethyl sulfoxide)scandium(III) ion
Dalton Transactions, 2004Co-Authors: Mikhail Yu. Skripkin, Patric Lindqvist-reis, János Mink, Ingmar Persson, Alireza Abbasi, Magnus SandströmAbstract:Hexakis(dimethyl sulfoxide)scandium(III) iodide, [Sc(OS(CH3)2)6]I3 contains centrosymmetric hexasolvated scandium(III) ions with an Sc–O bond distance of 2.069(3) A. EXAFS spectra yield a mean Sc–O bond distance of 2.09(1) A for solvated scandium(III) ions in dimethyl sulfoxide solution, consistent with six-coordination. Raman and infrared absorption spectra have been recorded, also of the Deuterated Compound, and analysed by means of normal coordinate methods, together with spectra of dimethyl sulfoxide. The effects on the vibrational spectra of the weak intermolecular C–H⋯O interactions and of the dipole–dipole interactions in liquid dimethyl sulfoxide have been evaluated, in particular for the S–O stretching mode. The strong Raman band at 1043.6 cm−1 and the intense IR absorption at 1062.6 cm−1 have been assigned as the S–O stretching frequencies of the dominating species in liquid dimethyl sulfoxide, evaluated as centrosymmetric dimers with antiparallel polar S–O groups. The shifts of vibrational frequencies and force constants for coordinated dimethyl sulfoxide ligands in hexasolvated trivalent metal ion complexes are discussed. Hexasolvated scandium(III) ions are found in dimethyl sulfoxide solution and in [Sc(OSMe2)6]I3. The iodide ion–dipole attraction shifts the methyl group C–H stretching frequency for (S–)C–H⋯I− more than for the intermolecular (S–)C–H⋯O interactions in liquid dimethyl sulfoxide.
Florian Schroder - One of the best experts on this subject based on the ideXlab platform.
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influence of deuteration on lithium acetate dihydrate studied by inelastic x ray scattering density functional theory thermal expansion elastic and thermodynamic measurements
Dalton Transactions, 2011Co-Authors: Florian Schroder, Eiken Haussuhl, A Bossak, Keith Refson, Björn Winkler, Bernard Hennion, J D Bauer, Victor Milman, M KrischAbstract:The influence of deuteration on the properties of lithium acetate dihydrate has been investigated by thermal expansion measurements, ultrasound spectroscopy and calorimetry. Inelastic X-ray scattering has been employed to investigate if the low temperature structural phase transition can be detected by a change in the vibrational spectrum. Density functional theory, DFT, calculations have been employed to complement the experimental investigations. The thermal expansion coefficients and the specific heat of the Deuterated Compound differ significantly from the protonated form. The differences in the elastic stiffness coefficients are just above the detection limit of the technique employed here. Temperature dependent inelastic X-ray spectroscopic measurements show no significant change of the vibrational spectrum when crossing the transition temperature. The DFT calculations show that the methyl group dynamics are best described in the framework of coupled rotators of opposing methyl groups. One of the coupled rotational modes corresponds to a hindered rotator with a barrier of 15 meV, while the other is a free rotator.
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low temperature structural phase transition in Deuterated and protonated lithium acetate dihydrate
The Journal of Chemical Thermodynamics, 2010Co-Authors: Florian Schroder, Eiken Haussuhl, P T Cong, M Avalosborja, Björn Winkler, Marc Quilichini, B. Wolf, Bernard HennionAbstract:Abstract Heat capacity measurements of protonated lithium acetate dihydrate show a structural phase transition at T = 12 K. This finding is in contrast to earlier work, where it was thought that only the Deuterated Compound undergoes a low temperature structural phase transition. This finding is confirmed by low temperature ultrasound spectroscopy, where the structural phase transition is associated with a velocity decrease of the ultrasonic waves, i.e. with an elastic softening. We compare the thermodynamic properties of the protonated and Deuterated Compounds and discuss two alternatives for the mechanism of the phase transition based on the thermal expansion measurements.
Mohamedally Kurmoo - One of the best experts on this subject based on the ideXlab platform.
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crystal and magnetic structures and magnetic properties of selenate containing natrochalcite aimii2 h3o2 seo4 2 where a na or k and m mn co or ni
Inorganic Chemistry, 2012Co-Authors: Wassim Maalej, Serge Vilminot, G Andre, Zakaria Elaoud, Tahar Mhiri, Mohamedally KurmooAbstract:The synthesis of a series of selenate containing natrochalcite, AIMII2(H3O2)(SeO4)2 where A = Na or K and M = Mn, Co, or Ni (here labeled as AMH and AMD for the hydrogenated and Deuterated Compound...
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Crystal and Magnetic Structures and Magnetic Properties of Selenate Containing Natrochalcite, AIMII2(H3O2)(SeO4)2 Where A = Na or K and M = Mn, Co, or Ni
Inorganic chemistry, 2012Co-Authors: Wassim Maalej, Serge Vilminot, G Andre, Zakaria Elaoud, Tahar Mhiri, Mohamedally KurmooAbstract:The synthesis of a series of selenate containing natrochalcite, AIMII2(H3O2)(SeO4)2 where A = Na or K and M = Mn, Co, or Ni (here labeled as AMH and AMD for the hydrogenated and Deuterated Compound...