Studies of the anisotropic self-diffusion and reorientation of butylammonium cations in the rotator phase of butylammonium chloride using 1H magnetic resonance, electrical conductivity and thermal measurements

1990 ◽  
Vol 86 (22) ◽  
pp. 3777 ◽  
Author(s):  
Mineyuki Hattori ◽  
Shin-ichi Fukada ◽  
Daiyu Nakamura ◽  
Ryuichi Ikeda
Keyword(s):  
Electrical Conductivity ◽  
Magnetic Resonance ◽  
Self Diffusion ◽  
Rotator Phase ◽  
Thermal Measurements

1H nuclear magnetic resonance, differential scanning calorimetry, and electrical conductivity studies on the phase transitions of pentylammonium chloride and the cationic self-diffusion in its rotator phase

1988 ◽  
Vol 66 (8) ◽  
pp. 1961-1969 ◽  
Author(s):  
Shigehiko Iwai ◽  
Ryuichi Ikeda ◽  
Daiyu Nakamura
Keyword(s):  
Phase Transition ◽  
Electrical Conductivity ◽  
Differential Scanning Calorimetry ◽  
Room Temperature ◽  
Stable Phase ◽  
Scanning Calorimetry ◽  
Nmr Studies ◽  
Self Diffusion ◽  
H Nmr ◽  
Rotator Phase

Measurements of 1H nmr, differential thermal analysis, and differential scanning calorimetry have revealed that solid pentylammonium chloride, cooled rapidly from room temperature, forms a mixture of the stable and metastable low-temperature phases below the phase transition temperature, Ttr (238 K). The sample annealed just below Ttr for 3 h was shown to consist of a single stable phase down to about 100 K, indicating the existence of a time-consuming phase transition taking place successively just below the normal transition. In the rotator phase obtainable above Ttr (257 K), 1H nmr studies proved the presence of axial rotation of the whole cation about the long axis, similar to n-paraffins in their rotator phase. Above room temperature, the onset of the translational self-diffusion of the cations within 2D planes in the layer structure of the rotator phase was detected by measuring the temperature dependence of electrical conductivity as well as 1H T1 and T1p. 2D self-diffusion constants and diffusional correlation times evaluated from the electrical conductivity observed between room and the melting temperatures indicate that the 2D cationic diffusion near the melting point is as fast as 3D self-diffusion in usual plastic crystals. Cationic motions in the two different rotator phases α and α′ are compared.

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