Sousa Amadeu, Nader de ; Grünberg, Bob ; Frydel, Jarek ; Werner, Mayke ; Limbach, Hans-Heinrich ; Breitzke, Hergen ; Buntkowsky, Gerd (2021)
Melting of Low Molecular Weight Compounds in Confinement Observed by ²H-Solid State NMR: Biphenyl, a Case Study.
In: Zeitschrift für Physikalische Chemie, 226 (11-12)
doi: 10.26083/tuprints-00019687
Artikel, Zweitveröffentlichung, Verlagsversion
Kurzbeschreibung (Abstract)
The ²H-NMR solid echo spectra of biphenyl molecules as guests in the mesopores of neat and silylated SBA-15 have been measured as a function of temperature. At low temperatures typical ²H-Pake patterns with parameters of (Qzz = 132 kHz, corresponding to Qcc = 176 kHz) and (η = 0.04) are observed. All samples exhibit a strong reduction of the melting point from the bulk value of 342.4 K to values between 222 K and 229 K, depending on both the pore diameter and the surface state and a glass like behavior of the biphenyl molecules in the melting regime. Employing the Roessler two-phase model of the modeling of glass-transitions by ²H-solid state NMR the distribution of activation energies for the rotational motions has been determined. At temperatures closely below the glass-transition temperature deviations from a static Pake pattern of an aromatic deuteron are observed, which indicate a pre-melting motion of biphenyl, which could be caused by C₂-ring flips of the phenyl rings.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2021 |
| Autor(en): | Sousa Amadeu, Nader de ; Grünberg, Bob ; Frydel, Jarek ; Werner, Mayke ; Limbach, Hans-Heinrich ; Breitzke, Hergen ; Buntkowsky, Gerd |
| Art des Eintrags: | Zweitveröffentlichung |
| Titel: | Melting of Low Molecular Weight Compounds in Confinement Observed by ²H-Solid State NMR: Biphenyl, a Case Study |
| Sprache: | Englisch |
| Publikationsjahr: | 2021 |
| Verlag: | De Gruyter |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Zeitschrift für Physikalische Chemie |
| Jahrgang/Volume einer Zeitschrift: | 226 |
| (Heft-)Nummer: | 11-12 |
| DOI: | 10.26083/tuprints-00019687 |
| URL / URN: | https://tuprints.ulb.tu-darmstadt.de/19687 |
| Zugehörige Links: | |
| Herkunft: | Zweitveröffentlichungsservice |
| Kurzbeschreibung (Abstract): | The ²H-NMR solid echo spectra of biphenyl molecules as guests in the mesopores of neat and silylated SBA-15 have been measured as a function of temperature. At low temperatures typical ²H-Pake patterns with parameters of (Qzz = 132 kHz, corresponding to Qcc = 176 kHz) and (η = 0.04) are observed. All samples exhibit a strong reduction of the melting point from the bulk value of 342.4 K to values between 222 K and 229 K, depending on both the pore diameter and the surface state and a glass like behavior of the biphenyl molecules in the melting regime. Employing the Roessler two-phase model of the modeling of glass-transitions by ²H-solid state NMR the distribution of activation energies for the rotational motions has been determined. At temperatures closely below the glass-transition temperature deviations from a static Pake pattern of an aromatic deuteron are observed, which indicate a pre-melting motion of biphenyl, which could be caused by C₂-ring flips of the phenyl rings. |
| Status: | Verlagsversion |
| URN: | urn:nbn:de:tuda-tuprints-196879 |
| Sachgruppe der Dewey Dezimalklassifikatin (DDC): | 500 Naturwissenschaften und Mathematik > 540 Chemie |
| Fachbereich(e)/-gebiet(e): | 07 Fachbereich Chemie 07 Fachbereich Chemie > Eduard Zintl-Institut > Fachgebiet Physikalische Chemie |
| Hinterlegungsdatum: | 01 Okt 2021 11:29 |
| Letzte Änderung: | 04 Okt 2021 06:03 |
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