Dithiolene complexes conductivity

Dithiolene complexes with the maleonitriledithiolate (mnt) ligand form highly delocalized systems and are widespread in studies of conducting and magnetic materials. The electronic properties have been extensively studied with various computational methods including Hiickel and extended Hiickel approaches to identify the nature of the orbitals involved in intramolecular and intermolecular interactions. These structural properties allow the complexes to interact in the solid state via short stacking S, S and short interstack S---S contacts.10 4-1048... 

New Molecular Architecture for Electrically Conducting Materials Based on Unsymmetrical Organometallic-Dithiolene Complexes... 

The anionic dithiolene complexes will form salts with tetrathiafulvalene. Expectations were that the solids would be highly conducting, but the products are insulators or semiconductors.1853... 

The tetrabutylammonium salts of the bis chelates are semiconductors but exhibit enhanced conducting properties after doping with iodine. The corresponding salts which are formed when Bi N is replaced by TTF+ or TSeF+ have higher conductivities than the analogous dithiolene complexes with magnitudes similar to that of TTF-TCNQ (TTF = tetrathiafulvalene, TSeF = tetraselenofulvalene, TCNQ = tetracyano-p-quinodimethane). 

A wide range of metal dithiolene complexes have been prepared and their electrical conduction properties reported.111-114 They include neutral, monoanion and dianion complexes with a variety of substituents on the ligand (R = Ph, Me, CN, H, CF3) and a variety of cations. The choice of cation has often been determined by the desire to obtain easily crystallized products and has resulted in the use of rather bulky substituted ammonium salts. The compounds behave as semiconductors with relatively low conductivities at room temperature. It has been shown that the monoanion complexes are considerably more conducting than either the corresponding neutral complex or the dianion, and Rosseinsky and Malpas have proposed that this is related to the ease of disproportionation.113... 

Most of the late transition metals (such as Fe, Co, Rh, Ir, Ni, Pd, Pt, Cu, Au, and Zn) have been found to form bis(dithiolene) complexes. A significant amount of work has been reported on the electronic structures and spectroscopy (32), redox properties (2), as well as the conductivity (33) of bis(dithiolene) complexes. Far less has been reported on their chemical reactivity. 

A great amount of research has focused on the electronic structure, spectroscopy, redox properties, and conductivity of homoleptic bis(l,2-dithiolene) complexes of c transition metal ions (51). The compounds are often highly... 

Finally, in Section IV dithiolene complexes with interesting optical properties, such as strong near-IR (NIR) absorption, nonlinear optical behavior, and the use of some dithiolene complexes for optical data storage will be reviewed. In Section V, attempts toward coupling conducting, and magnetic or optical properties will be discussed briefly. 

The (BMDT-TTF)JC[Ni(dcit)2] compound (see Scheme 12) involves the (BMDT-TTF) donor CgH4Sg, bis(methylenedithio)tetrathiafulvalene] (187) and the Ni(dcit)2 heterocyclic dithiolene complex (dcit2- = [C4N2S3]2-). Room temperature conductivity was reported to be 20-40 S cm 1 and the... 

Likewise, the first dithiolene complex-based magnet, (Cp2Mn)[Ni(dmit)2] (350), is a semiconductor, as could be expected from its stoichiometry, and the magnetic properties of further oxidized conducting species (CpjMn fN dmiQJ remain to be determined (531). 

In conclusion, at this point one must admit that no dithiolene complex-based compound exhibits a real interplay of conductivity and magnetism. This finding should not result in some kind of inferiority complex, as in only one single molecule-based system, L-(BETS)2FeCl4 and derived mixed Fe—Ga, or Cl— Br species, has it been unambiguously proven that conduction electrons may interact with localized spins (533). 

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