39105-74-3Relevant articles and documents
Molecular Motion in Solid X, X = Cl, Br, I, PF6, and BF4. 1H, 19F NMR Second Moment and Crystal Structure
Burbach, Guenter,Dou, Shi-Qi,Weiss, Alarich
, p. 1302 - 1309 (2007/10/02)
The tumbling motion of the tetramethylstibonium cation (+) has been studied in the ionic compounds X, X = Cl, Br, I, PF6, and BF4, by measurement of the second moment of the protons M2(1H) in the temperature range 95 I was determined by single crystal X-ray diffraction: a = 728.4(3) pm, c = 1037.7(5) pm, space group C6v4-P63mc, Z = 2. - M2(1H) of I shows cation tumbling at T > 320 K.The methyl groups are rotating about their threefold axes in the whole temperature range studied. - In PF6 and BF4 both, cation and anion are tumbling at T >/= 259 K and T >/= 248 K, respectively, as seen by M2(1H) and M2(19F).A jump in the second moments and differential thermal analysis (DTA) of BF4 reveals a solid-solid phase transition with hysteresis (width 28 K).Activation energies for the tumbling motion of the tetramethylstibonium cation have been determined. - Complex Compounds / Crystal Structure / Molecular Dynamics / Phase Transitions / Spectroscopy, Nuclear Magnetic Resonance
