Unique structural and physical properties of Ni(dmit)(2) anion radical salts characterized by short Te center dot center dot center dot S contacts (dmit=1,3-dithiole-2-thione-4,5-dithiolate)

摘要

Five new Ni(dmit)(2) anion radical salts, [Me3Te][ Ni(dmit)(2)](2) (1), [Me3Te][ Ni(dmit)(2)](3).(CH3)(2) C(O) (2), alpha-[MOT] [ Ni(dmit)(2)](2) (3), beta-[MOT][Ni(dmit)(2)](2) (4), and gamma-[MOT][Ni(dmit)(2)](2) (5) (dmit = 1,3-dithiole-2-thione-4,5-dithiolate; MOT = 1-oxa-4-methyl-4-telluracyclohexane) have been prepared by galvanostatic electrolysis. X-Ray crystal structure analyses show that all the salts are characterized by short Te...S contacts (3.41-3.85 Angstrom) between the anions and cations. Each salt shows unique molecular packing of the Ni( dmit)(2) units. The electronic structures are strongly dependent on these unique molecular arrangements. Among them, 1 and 3 show metallic behavior (down to 60 and 160 K, respectively) and the resistivity of 4 is almost independent of temperature, increasing moderately below 40 K. [References: 56]