wizyta

od 2020-09-20

Title: Molecular dynamics of n-dodecylammonium chloride studied by nuclear magnetic resonance

Source: Applied Magnetic Resonance

Year : 2000

Abstract:

The relation between molecular dynamics and phase properties of the bilayered compound C12H25NH3Cl is studied by differential scanning calorimetry, proton second moment, and spin-lattice relaxation Limes. In the low-temperature Phase I of the compound methyl and ammonium groups execute a classical threefold reorientation, while the alkylammonium chains are rigid on the nuclear magnetic resonance time scale. In the intermediate-temperature phase delta a trans-gauche isomerization of the alkyl chains is observed. In the high-temperature phase alpha the reorientation of the whole chains about their long axes, which are parallel to the normal to the ionic layer is evidenced. In the meta-stable epsilon phase the dynamics involves classical rotation of methyl and ammonium groups and CH2 groups motion of the trans-gauche isomerization type.

DOI: 10.1007/BF03162384   (Pobrane:  aktualizowanie)