Molecular dynamics of the methylammonium cation in [CH3NH3]5Bi2Cl11.
The 1H relaxation times T1 of methylammonium in chlorobismuthate(III) were measured in the temperature range from 50 to 270 K with a SXP 4/100 Bruker pulse spectrometer at 55.2 MHz. It was found that the T1 temperature dependence has three minima. The individual relaxation rates of the three-proton groups can be described by the O'Reilly and Tsang formula. The results obtained from the fitting procedure, using the typical Woessner formula for complex compounds, allow to conclude that the low-temperature minimum is due to the relaxation of all CH3 groups and the other two minima are due to the relaxation of two and four NH3 groups, respectively. This assignment is based on the X-ray results showing that methylammonium cations are differently bonded in this crystal.
Medycki
W
W
Institute of Molecular Physics, Polish Academy of Sciences, Poznań.
Piślewski
N
N
Jakubas
R
R
D002412:Cations / Q000737:chemistry; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D017709:Fractals; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D008744:Methylamines / Q000737:chemistry*; D008956:Models, Chemical; D013696:Temperature
D002412:Cations; D008744:Methylamines; C027451:methylamine