Dynamic characterization of crystalline and glass phases of deuterated 1,1,2,2 tetrachloroethane
| Autor: | Alberto Wolfenson, Philippe Négrier, Josep Ll. Tamarit, Mariano Zuriaga, S. C. Perez, Pablo Serra |
|---|---|
| Přispěvatelé: | Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. GCM - Grup de Caracterització de Materials, Facultad de Matemática, Astronomía y Física [Cordoba] (FaMAF), Universidad Nacional de Córdoba [Argentina], Laboratoire Ondes et Matière d'Aquitaine (LOMA), Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Departament de Fisica i Enginyeria Nuclear (ETSEIB), Universitat Politècnica de Catalunya [Barcelona] (UPC), CONICET and SECYT-UNC of Argentina and the Spanish Ministry of Science and Innovation (Grant No. FIS2014-54734-P), the Catalan Government (Grant No. 2014 SGR-581) |
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Materials science
Magnetic-resonance FOS: Physical sciences General Physics and Astronomy Molecular dynamics Temperature-dependence Condensed Matter::Disordered Systems and Neural Networks Crystal Nuclear-quadrupole resonance Phase (matter) Physics - Chemical Physics Molecular crystals [CHIM.CRIS]Chemical Sciences/Cristallography Molecular symmetry Molecular-dynamics Dinàmica molecular Physical and Theoretical Chemistry Physics::Chemical Physics Force-field Chemical Physics (physics.chem-ph) Vidre Relaxation (NMR) Spin-lattice-relaxation Tetrachloroethane Amorphous solid Condensed Matter::Soft Condensed Matter Crystallography Física::Física molecular [Àrees temàtiques de la UPC] Chemistry Physical and theorical Glass Nuclear quadrupole resonance Glass phases Enginyeria química::Química física [Àrees temàtiques de la UPC] Fisicoquímica |
| Zdroj: | e-ISSN: 1089-7690 Repositorio Digital Universitario (UNC) Universidad Nacional de Córdoba instacron:UNC UPCommons. Portal del coneixement obert de la UPC Universitat Politècnica de Catalunya (UPC) Journal of Chemical Physics Journal of Chemical Physics, American Institute of Physics, 2015, 143 (13), pp.134502 (1-8). ⟨10.1063/1.4931824⟩ Recercat. Dipósit de la Recerca de Catalunya instname |
| ISSN: | 0021-9606 1089-7690 |
| Popis: | A thorough characterization of the {\gamma}, {\beta} and glass phases of deuterated 1,1,2,2 Tetrachloroethane (C2D2Cl4) via Nuclear Quadrupole Resonance and Molecular Dynamic Simulations (MDS) is reported. The presence of molecular reorientations was experimentally observed in the glass phase and in the {\beta} phase. In the {\beta} phase, and from MDS, these reorientations are attributed to two possible movements, i.e. a $180^o$ reorientation around the C2 molecular symmetry axis and a reorientation of the molecule between non-equivalent positions. In the glass phase, the spin-lattice relaxation time T1 is of the order of 16 times lower that T1 in the crystalline phase and varies as $T^{-1}$ below 100 K in good agreement with the strong quadrupolar relaxation observed in amorphous materials and in the glassy state of molecular organic systems. The activation energy of molecular reorientations in the glass phase (19 kJ/mol) is comparable to that observed in the glassy crystal of a "molecular cousin" compound, Freon 112 (C2F2Cl4), for the secondary {\beta}-relaxation. Moreover, the on-site orientational motion of Tetrachloroethane molecules offers a new indirect evidence of the prominent role of such orientational disorder in glassy dynamics. Comment: Journal of Chemical Physics (in press) |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|