New 1:3 Type Nickel-Bis(dithiolene) Salt (FcCHCHPymCH 3 )[Ni(dmit) 2 ] 3 (dmit: 2-Thioxo-1,3-dithiole-4,5-dithiolate): Its Electrocrystallization, Crystal Structure, Electrical Properties, and Electronic Band Structure Analysis Yoon-Kyoung Han, † Dong-Kyun Seo,* ,‡ Haeyong Kang, § Woun Kang, § and Dong-Youn Noh* ,† Department of Chemistry, Seoul Women’s UniVersity, Seoul 139-774, Korea, Department of Chemistry and Biochemistry, Arizona State UniVersity, Tempe, Arizona 85287-1604, and Department of Physics, Ewha Womans UniVersity, Seoul 120-750, Korea Received February 27, 2004 Black single crystals of Ni(dmit) 2 complex (dmit: 2-thioxo-1,3-dithiole-4,5-dithiolate) with trans-4-[2-(1-ferrocenyl)- vinyl]-1-methylpyridinium chromophore as a countercation, (FcCHCHPymCH 3 )[Ni(dmit) 2 ] 3 , were prepared by the electrocrystallization technique. In the triclinic structure of the complex (P1 h, a ) 11.430(5) Å, b ) 13.349(2) Å, c ) 19.355(6) Å, R) 75.15(2)°,  ) 79.19(3)°, γ ) 82.12(2)°, Z ) 2), Ni(dmit) 2 anion layers are separated by the cations with a relatively rare 1:3 cation-to-anion ratio. Detailed crystal and electronic structure analysis revealed that the anions are stacked in the layers to form alternating dimers and monomers rather than trimers. The measured electrical conductivity indicates a semiconducting property of the compound with an estimated energy gap of 0.06 eV. The calculated LUMO bands are very narrow, and the semiconducting behavior is more likely due to the electron localization mainly on the dimers, consistent with the observed longer Ni-S bond distances in the dimers. Introduction The nickel complex (1) of dmit 2- (2-thioxo-1,3-dithiole- 4,5-dithiolate) has been utilized to obtain molecular con- ductors, superconductors, magnets, and nonlinear optical materials, since the discovery of the first superconducting charge-transfer salt containing the transition-metal complex, TTF[Ni(dmit) 2 ]. 1 The partially oxidized electronic state of the [Ni(dmit) 2 ] δ- molecule (δ < 1) is an essential require- ment for the high conductivity of the salts, 2 and yet previous research efforts have found that the stacking arrangements of the Ni(dmit) 2 molecules in the crystal structure are also very important in determining the magnitude of the orbital interactions between the adjacent complex molecules. Weak orbital interactions often provide Ni(dmit) 2 units bearing unpaired electrons, and their magnetic interactions are again governed by how the partially filled molecular orbitals (MOs) of Ni(dmit) 2 anions interact with each other. Therefore, to design customized functional materials from Ni(dmit) 2 salts having the requisite electronic properties, it is essential to understand the correlation between the electronic structures of the salts and the molecular arrangements in their crystal structure. Among the many Ni(dmit) 2 salts studied so far, those compounds with an anion:cation ratio of 3 are rather rare, and only a handful of them have been reported in the literature. 1a,3-8 However, the reported stack modes of the Ni(dmit) 2 anion complex are extremely diverse, depending * Author to whom correspondence should be addressed. E-mail: dynoh@ swu.ac.kr. † Seoul Women’s University. ‡ Arizona State University. § Ewha Womans University. (1) (a) Bousseau, M.; Valade, L.; Legros, J.; Cassoux, P.; Garbauskas, M.; Interrante, L. V. J. Am. Chem. Soc. 1986, 108, 1908. (b) Cassoux, P.; Valade, L.; Kobayashi, H.; Kobayashi, A.; Clark, R. A.; Underhill, A. E. Coord. Chem. ReV. 1991, 110, 115. (c) Cassoux, P. Coord. Chem. ReV. 1999, 185-186, 213. (d) Pullen, A. E.; Olk, R.-K. Coord. Chem. ReV. 1999, 188, 211. (e) Akutagawa, T.; Nakamura, T. Coord. Chem. ReV. 2002, 226, 3. (2) (a) Akutagawa, T.; Takamatsu, N.; Shitagami, K.; Hasegawa, T.; Nakamura, T.; Inabe, T.; Fujita, W.; Awaga, K. J. Mater. Chem. 2001, 11, 2118. (b) Fujiwara, M.; Kato, R. J. Chem. Soc., Dalton Trans. 2002, 3763. (3) (a) Pomarede, B.; Garreau, B.; Malfant, I.; Valade, L.; Cassoux, P.; Legros, J.; Audouard, A.; Brossard, L.; Ulmet, J.; Doublet, M.; Canadell, E. Inorg. Chem. 1994, 33, 3401. (b) Johansen, I.; Bechgaard, K.; Rindorf, G.; Thorup, N.; Jacobsen, C. S.; Mortensen, K. Synth. Met. 1986, 15, 333. Inorg. Chem. 2004, 43, 7294-7300 7294 Inorganic Chemistry, Vol. 43, No. 23, 2004 10.1021/ic0497432 CCC: $27.50 © 2004 American Chemical Society Published on Web 10/12/2004