Crystal structure, NMR study, dc-conductivity and dielectric relaxation studies of a new compound [C₂H₁₀N₂]Cd(SCN)₂Cl₂

¹ Laboratoire de Génie des Matériaux et Environnement, ENIS, 1173, Université de Sfax, Tunisia
² Laboratoire de l’état solide, Faculté des sciences de Sfax, B.P.1171, 3000 Sfax, Tunisia

¹ e-mail: khaoulaslaheddine@yahoo.fr

Abstract

The crystal structure, the solid NMR spectroscopy and the complex impedance study have been carried out on [C₂H₁₀N₂]CdCl₂(SCN)₂. Characterization by single crystal X-ray crystallography shows that the cadmium atoms have à 2N2S2Cl hexa-coordination sphere, exhibiting pseudo-octahedral geometry. The cadmium atoms are bridged by two thiocyanate ions generating 1-D polymeric-chains. These chains are themselves interconnected by means of N-H…Cl(NCS) hydrogen bonds originating from the organic cation [(NH₃)₂(CH₂)₂]²⁺. ¹¹¹Cd isotropic chemical shifts span a range of 268ppm. The cadmium atom exhibits multiplets that result from ¹¹¹Cd-¹⁴N spin-spin coupling. Examination of ¹¹¹Cd and ¹³C MAS line shapes shows direct measurement of the indirect spin-spin coupling constant ²J(¹¹¹Cd, ¹⁴N) = 105Hz and the dipolar coupling constant of 1381Hz . Impedance spectroscopy measurements of [C₂H₁₀N₂]CdCl₂(SCN)₂ have been studied from 209Hz to 5 MHz over the temperature range 300-370 K. The Cole-Cole (Z” versus Z’) plots are fitted to two equivalent circuits models. The formalism of complex permittivity and impedance were employed to analyze the experimental data. The dc conductivity follows the Arrhenius relation with an activation energy E_a = 0.54 (3) eV.