| Abstract: | The N‐N dimethyl benzylammonium tetrachlorothallate (III) [C6H5CH2NH(CH3)2]TlCl4 crystallizes in the monoclinic system P21/n at room temperature with the following unit cell dimensions: a = 7.725(3) Å, b = 14.080(5) Å, c = 13.697(4) Å, β = 91.2(2)° with Z = 4. The structure shows a layer arrangement perpendicular to the b axis: planes of [TlCl4]‐ tetrahedra alternate with planes of [C6H5CH2NH(CH3)2]+ cations. The cohesion of the atomic arrangement is ensured by hydrogen bonds N‐H…Cl. Differential scanning calorimetric and optical birefringence measurements reveals a phase transition at T = 339K. Raman spectroscopic study and dielectric measurements were performed to discuss the mechanism of the phase transition. (© 2007 WILEY ‐VCH Verlag GmbH & Co. KGaA, Weinheim) |
