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The Z and E isomers of the iodinated TTF derivative (Z,E)-Me2I2-TTF co-crystallize in a mixed-valence salt with Br− anions, and are segregated into Z and E stacks, each of them with a different charge localization pattern, which also revealed charge-assisted halogen bonding. [ABSTRACT FROM AUTHOR]

A novel 1D hybrid salt (MQ)[CuBr2]∞ (MQ = N-methylquinoxalinium) is reported. Structural, spectroscopic and magnetic investigations reveal a minimal CuII doping of less than 0.1%. However it is not possible to distinguish CuI and CuII. The unusually close packing of the organic moieties and the dark brown colour of the crystals suggest a defect electronic structure. [ABSTRACT FROM AUTHOR]

BOOK REVIEW Surfactants and Polymers in Drug Delivery. Drugs and the Pharmaceutical Sciences. Volume 122 by Malmsten, Martin

The single crystal X-ray structure of the all-axial conformer of the (R,R,R,R) enantiomer of the chiral donor tetramethyl-BEDT-TTF (TM-BEDT-TTF) was described and compared to the all-equatorial conformer. (S,S,S,S)-Tetramethyl-BEDT-TTF formed crystalline 1:1 complexes with TCNQ and TCNQ-F4, as well as a THF solvate of the TCNQ complex. Donors bis((2S,4S)-pentane-2,4-dithio)tetrathiafulvalene and (ethylenedithio)((2S,4S)-pentane-2,4-dithio)tetrathiafulvalene, which contain seven-membered rings bearing chirally oriented methyl groups, only formed complexes with TCNQ-F4. The TCNQ-F4 complexes contain planar organosulfur systems, in contrast to the TCNQ complexes in which there is minimal charge transfer. A variety of crystal packing modes were observed. Electrocrystallization experiments with both enantiomers and the racemic form of tetramethyl-BEDT-TTF afforded mixed valence radical cation salts with the AsF6 and SbF6 anions formulated as (TM-BEDT-TTF)2XF6 (X = As, Sb). Electrical conductivity was only found in one charge transfer complex, while the radical cation salts are all semiconducting. [ABSTRACT FROM AUTHOR]

A mixed-valence salt of tTTF-I with ClO4 -, formulated as (tTTF-I)2ClO4, is characterized by the presence of two crystallographically independent donor molecules, segregated in different layers and linked together through I...O interactions with the ClO4 - anion disordered at room temperature. The tTTF-I donor molecule was prepared by metallation of tTTF (trimethylene tetrathiafulvalene) followed by reaction with iodine to afford the mono and diiodo derivatives tTTF-I and tTTFI2, respectively. The crystal structure of the latter neutral tTTFI2 shows the occurrence of strong type II, I...I halogen bond interactions. Band structure calculations of the dual-layer structure of the 2 : 1 salt (tTTF-I)2ClO4 show co-existence of both 1D open and 2D closed Fermi surfaces. The salt undergoes a metal-insulator phase transition at TMI = 90 K, associated with an electronic dimensionality decrease, since already at 100 K, the 2D part of the Fermi surface transforms into 1D corrugated planes. High resolution X-ray investigations performed at 100 K, combined with multipolar refinements, indicate an approximately equivalent +0.5e charge in both donor molecules, as also deduced from the intramolecular bond distances. On the other hand, Raman spectroscopic investigations show that at ambient temperature the charge is actually distributed non-uniformly in conducting layers of tTTF-I molecules, with the identification of molecules with charges +1, +0.5, 0e, while at low temperature the charge distribution becomes essentially uniform (+0.5e), as confirmed from the X-ray high resolution data. These apparently contradictory behaviors are actually a consequence of a partial electron transfer between the two independent slabs to reach a common Fermi level in the metallic phase. [ABSTRACT FROM AUTHOR]

Oxidation of diiodoethylenedithiotetrathiafulvalene (EDT-TTF-I2), C8H4I2S6, with the strong oxidizer tetrafluorotetracyanoquinodimethane (TCNQF4), C12F4N4, affords, depending on the crystallization solvent, two polymorphs of the 2:1 charge-transfer salt (EDT-TTF-I2)2(TCNQF4), represented as D2A. In both salts, the TCNQF2 is reduced to the radical anion state, and is associated through short C-I. . .NC halogen bonds to two EDT-TTF-I2 molecules. The two polymorphs differ in the solid-state association of these trimeric D-A-D motifs. In polymorph (I) the trimeric motif is located on an inversion centre, and hence both EDT-TTF-I2 molecules have +0.5 charge. Together with segregation of the TTF and TCNQ derivatives into stacks, this leads to a chargetransfer salt with high conductivity. In polymorph (II) two crystallographically independent EDT-TTF-I2 molecules bear different charges, close to 0 and +1, as deduced from an established correlation between intramolecular bond lengths and charge. Overlap interactions between the halogen-bonded D0-A-•-D+• motifs give rise, in a perpendicular direction, to diamagnetic A22- and D0-D22+-D0 entities, where the radical species are paired into the bonding combination of respectively the acceptor LUMOs and donor HOMOs. The strikingly different solid-state organization of the halogen-bonded D- A-D motifs provides an illustrative example of two modes of face-to-face interaction between π-type radicals, into either delocalized, uniform chains with partial charge transfer and conducting behaviour, or localized association of radicals into face-to-face A22- and D22+ dyads. [ABSTRACT FROM AUTHOR]

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]