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A novel method of synthesizing {AcrH}{Ni(dmit)(sub 2)}(sub 3) and {PheH}{Ni(dmit)(sub 2)}(sub 3) was developed as well as their structures were determined through x-ray crystallography. Results have shown that the crystal structures of the two compounds were very distinct from each other. The former compound exhibited metallic conductivity behavior, while the latter displayed a semimetallic conductivity behavior.

The electrocrystallization of diiodo- and dibromo-ethylenedithiotetrathiafuvalene (EDT-TTFI[sub2] and EDT-TTFBr[sub2]) in the presence of the polymeric 1D [Et[sub4]N][Cd(SCN)[sub3]] as an electrolyte affords two different salts, formulated as [EDT-TTF-I[sub2]][sub4][Cd[sub3](NCS)[sub8]] • CH3CN H[sub2]O (1) and [EDT-TTF-Br[sub2]][sub10][Cd[sub5](SCN)[sub14]] • 2TCE (2), characterized by a two- dimensional segregation of the partially oxidized donor molecules and the polymeric anionic network incorporating embedded solvent molecules. Both salts exhibit a partial charge transfer, that is, p = 0.5 in 1 and an unconventional p = 0.4 in 2. They behave as semiconductors with σ[subRT] = 0.67 and 33 S cm[sup-1] and activation energies of 330 and 370 K for 1 and 2, respectively. Compared with a 1:3 Cd/SCN ratio of the starting electrolyte, the reconstructed, thiocyanate (SCN)-deficient motifs [Cd[sub3](NCS)[sub8]][sub2] and [Cd[sub5](SCN)[sub14]][sub4] organize into layered hollow structures with cavities filled by solvent molecules, halogen-bonded to the halogenated TTF molecules, through a C[subTTF]—N≡C—CH[sub3] interaction in 1, through a type II C[subTTF]—Br⋯CI-CTCE halogen/halogen interaction in 2. Band structure and Fermi surface calculations for the two salts indicate a two-dimensional character, while the semiconducting properties of the salts are attributed to an efficient nesting of the hidden 1D Fermi surfaces. [ABSTRACT FROM AUTHOR]

An efficient synthetic procedure for the preparation of unsymmetrically substituted tetrathiafulvalene (TTF) donors has been used to obtain the trimethylene-tetrathiafulvalene (tTTF) donor with high purity. Good quality crystals of the two (tTTF)(2)X (X = Br, I) salts have been obtained by electrocrystallization. The two salts are isomorphous and contain tTTF layers which are built from (tTTF)(2) dimeric units. Both systems are low-dimensional antiferromagnets with the highest Néel temperatures for TTF based radical cation salts: ≈ 35 K (Br salt) and ≈43 K (I salt). The resistivity is found to substantially decrease with pressure although both salts still have activated conductivity at 25 kbar. First-principles Density Functional Theory (DFT) calculations have been used to investigate the relative strength of the three different types of magnetic interactions in the tTTF layers as well as the potential magnetic ground states. These calculations successfully predict the nature of the ground state and suggest a possible correlation between structural details and Néel temperatures for the bromine and iodine salts. Remarkably, the calculated antiferromagnetic ground state can be predicted from the nesting properties of the Fermi surface for the hypothetical Pauli paramagnetic metallic state., (© 2011 American Chemical Society)