In:
CrystEngComm, Royal Society of Chemistry (RSC), Vol. 23, No. 37 ( 2021), p. 6620-6625
Abstract:
Electrical resistivity measurements of a dual layered organic conductor (ET) 4 ZnBr 4 (1,2-C 6 H 4 Cl 2 ) above room temperature show abrupt changes in resistivity at 320 K. Single-crystal X-ray diffraction studies in the 100–350 K range show polymorphic transformation at T p ∼320 K, indicating that the crystals belong to the tetragonal system (high-temperature phase, HT-phase) above T p and to the triclinic system (low-temperature phase, LT-phase) below T p with abrupt phase transition from the HT-phase to the LT-phase. During the sequential heating of the crystal, anharmonic effects are detected in the 260–315 K range: i) an increase in growth of rate of parameter a and rate of the mean-square atomic displacements of the [ZnBr 4 ] 2− anions; ii) an increase in the amplitudes of thermal vibrations of ET and solvent molecules. The structure near the phase transition at 315 K reveals splitting of the positions of ethylene groups of ET, demonstrating for the first time that for the (ET) 4 MBr 4 (1,2-C 6 H 4 Cl 2 ) family disordering of the ET occurs in the LT-phase when approaching T p . The final rearrangement of the structure from the triclinic LT-phase to the tetragonal HT-phase occurs above 315 K.
Type of Medium:
Online Resource
ISSN:
1466-8033
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2021
detail.hit.zdb_id:
2025075-7
Permalink