Dielectric anisotropy of the single crystal of isopropylviologen copper(I) triiodide.

Solvothermal reactions of CuI with isopropanol, 4,4'-bipyridine, I(2) and a small amount of water in MeCN produced one coordination compound [isopropylviologen][CuI(3)] (isopropylviologen = N,N'-diisopropyl-4,4'-bipyridinium) (1). The dielectric constants of the single crystal of 1 along the three crystal axes are different with the largest diversity ratio of ∼3.3, showing dielctric anisotropic behavior. Under low temperature (<273 K) or medium electric field frequency range (1 KHz-1 MHz), the dielectric constant of the title compound is nearly unchanged, exhibiting a temperature/frequency-independent characteristics. The crystalline powder of 1 has a low dielectric constant and low dielectric loss in the medium electric field frequency range, which is comparable to the traditional low-k material SiO(2).