NMR and molecular dynamics in the choline ion

摘要: Proton magnetic resonance spectra of three crystalline choline halides have been obtained over a temperature range 77 to 440 °K. In all these materials the line shapes are strong functions with multiple changes observed for each substance. Above 353 °K, at which crystal–crystal phase transition occurs, second moment 0.9 G2 chloride reflects presence isotropic reorientation ions in solid. This is just extremely high radiation sensitivity ceases, suggesting that existence this dynamic behavior renders crystal incapable supporting decomposition reaction below temperature. Similar also bromide higher From dependence correlation frequency, activation energies motional processes were determined and found be 3–4 kcal/mole low 12–15 hig...