Structures, energy bands and conductivities of (Me3NEt)[Pd(dmit)2]2 and (NEt4)- [Pd(dmit)2

Abstract

The electrical conductive molecular crystals (Me3NEt)[Pd(dmit) 2]2 and (NEt4)[Pd (dmit) 2]2 (dmit = 4,5-dimercapto-1,3-dithiole-2-thione) have been prepared, and their crystal structures and conductivity-temperature curves have been determined. The fact that the conductivity at room temperature of (Me3NEt)[Pd(dmit) 2]2 (σ = 58 Ω-1 cm-1) is much higher than that of (Net4)-[Pd(dmit)2]2 (σ = 2.2 Ω-1.cm-1) has been rationally explained by the results of energy band calculations. (MeNEt3)[Pd(dmit)2]2 belongs to monoclinic system, P21/m space group and (Net4)[Pd (dmit)2]2 belongs to triclinic system, \(P\bar 1\) space group. The structural conducting component of the crystals is the planar coordinative anion [Pd(dmit)2]0.5- which forms the face-to-face dimmer. [Pd(dmit)2]- 2These dimers have been further constructed to be a kind of two-dimensional (2-D) conductive molecular sheet by means of S_S intermolecular interactions. The tiny difference of the above 2-D molecular sheets of the two title crystals has resulted in one order of magnitude difference of conductivities.