0000000000608970
AUTHOR
N. Piślewski
showing 2 related works from this author
DSC, Dilatometric, Dielectric, and1H NMR Studies of Phase Transitions and Molecular Motions in [N(C2H5)4]3M2Cl9 (M = Sb, Bi) Crystals
1995
Results in the dependence of stoichiometry of obtained tetraethylammonium (TEA) chloroantiomonate and chlorobismuthate salts on the molar ratio of reactants used in the synthesis are presented. Seven tetraethylammonium salts are obtained: (TEA) 6 M 8 Cl 30 , TEAMCI 4 , (TEA) 3 M 2 Cl 9 (M = Sb, Bi) and (TEA) 2 SbCl 5 . Preliminary X-ray diffraction studies on (TEA) 3 M 2 Cl 9 (M = Sb, Bi) show that they are isomorphous, crystallizing at room temperature in monoclinic symmetry. The dilatometric, dielectric, and DSC studies show that (TEA) 3 Bi 2 Cl 9 undergoes two phase transitions at T c2 = 144 K and at T c1 = 322 K while (TEA) 3 Sb 2 Cl 9 undergoes three transitions at T c3 = 185, T c2 = 2…
1H NMR, DSC, dielectric, and dilatometric studies of phase transitions and molecular dynamics in N (C2H5)4SbCl4
1994
The results of dielectric, dilatometric, 1H NMR, and DSC studies on N(C2H5)4SbCl4 crystals are presented. The title compound undergoes two phase transitions at Tc1 = 272 K reversible of first order and at Tc2 = 393 K irreversible. The values of transition entropies and enthalpies are compared with those of other tetraethylammonium halogenoantimonates and bismuthates (III). The spin-lattice relaxation times and the values of the second moments of the 1H NMR line for the N(C2H5)4SbCl4 crystal are measured in the temperature range of 70 to 400 K. Two minima of T1 are observed. They are attributed to CH3 group reorientations. The activation energies for the processes are determined.