One-dimensional bromo-bridged Ni-III complexes [Ni(S,S-bn)(2)Br]Br-2 (S,S-bn=2S,3S-diaminobutane): Synthesis, physical properties, and electrostatic carrier doping

A new bromo-bridged Ni-III. compound has been synthesized. This compound displayed a strong antiferromagnetic interaction between spins located on Ni-III species (J=(2350 +/- 500) K) that result from the strong covalency of the Ni-Br bond and the spin-Peierls transition below 150K. This was shown by the results of magnetic susceptibility and Br-81 nuclear quadrupole resonance spectroscopy analysis. We succeeded in the electrostatic carrier doping of a single crystalline sample by using a field-effect transistor device. This compound also showed n-type semiconductor behavior, which can be reasonably rationalized by the existence of a small amount of Ni-II impurities.