Controlling and measuring conformational properties of n -alkane ultraconfined in urea: A high-pressure 2 H NMR study

Autor:	C. Odin, J. C. Ameline
Rok vydání:	2004
Předmět:	Alkane chemistry.chemical_classification chemistry.chemical_compound Nuclear magnetic resonance Chemistry Helium pressure Analytical chemistry Urea General Physics and Astronomy Volume change Conformational isomerism
Zdroj:	Europhysics Letters (EPL). 66:378-384
ISSN:	1286-4854 0295-5075
DOI:	10.1209/epl/i2003-10221-1
Popis:	2H high-resolution solid-state NMR experiments were performed on the intergrowth compound C19D40/urea at ambient temperature and helium pressure up to 4500 bars in a home-made NMR probe. These experiments show that the populations of chain ends gauche conformers can be reversibly modified with pressure. The trans-gauche volume change ~ 10 ? 2 ?3, free-energy change ?Fgt = 5 ? 0.7 kJ/mol as well as the contribution of the conformational defects to the chain spring constant Cgt ~ 8 ? 4 N/m were estimated for the first time for an ultraconfined n-alkane.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::79b18dd58316a277b7134f400d6141f3 https://doi.org/10.1209/epl/i2003-10221-1 Zobrazit plný text záznamu