Efficient syntheses are reported for tetraiodotetrathiafulvalene 2, 4-iodo-5-methyl-4',5'-bis(methylsulfanyl)TTF 3, and 4-iodo-4',5'-bis(methylsulfanyl)TTF 4 by iodination, using perfluorohexyl iodide, of lithiated derivatives of the corresponding TTF system. Bromination and chlorination of lithiotrimethylTTF using 1,2-dibromotetrafluoroethane and hexachloroethane gave 4-bromo-and 4-chloro-4',5,5'-trimethylTTF 6 and 7, respectively. Phosphite-induced self-coupling or cross-coupling reactions of 4-iodo-1,3-dithiole-2-thione or 4,5-diiodo-1,3-dithiole-2-thione(one) half-units resulted in TTF derivatives with partial loss of the iodine substituent(s). 4,5-Dibromo-4',5'-bis(cyanoethylsulfanyl)TTF 15 was prepared by cross-coupling methodology, and converted into 4,5-dibromo-4',5'-bis(methylsulfanyl)TTF 16 by reaction with caesium hydroxide and then methyl iodide. EPR data are reported for the electrochemically generated cation radicals of trimethylTTFX derivatives (X~I, Br and Cl) 5-7, respectively. For the neutral donors, the X-ray crystal structures are reported for 2, 5, 6, tetramethylTTF 8 and 15. Structure 2 is characterised by a particularly dense packing with continuous chains of intra-stack I … I contacts (4.17-4.19 A ˚). The crystals of 6 and 8 are isomorphous, while the structure of 5 is different. The iodo-substituent in 5 affects the packing in a way the bromo-substituent in 6 does not, due to differences in specific interactions rather than steric demands of I and Br, which are similar. Structure 15 comprises face-to-face dimers with inter-dimer Br … Br (3.57 A ˚) and Br … S (3.55 A ˚) contacts: a remarkable difference in bond distances between the Br and S-substituted dithiole rings is observed. The 1 : 1 charge-transfer (CT) complexes 3?TCNQ and 4?TCNQ (TCNQ~7,7,8,8-tetracyano-p-quinodimethane, 17) display mixed stair-like stacks of alternating D and A moieties: the overall degree of CT is estimated from bond length analysis to be 0.2 e and 0.3 e, respectively. In 3?TCNQ either position of the disordered iodine atom has one short (inter-stack, but intra-layer) contact with a cyano group (I … N distances of 3.14 and 3.18 A ˚). In 4?TCNQ a similar I … N contact is much longer (3.35 A ˚). In the structure of 5 z? I 3 2 ? 1 2I2 the cation radical is disordered; dimeric cation radicals display short intra-dimer contacts (S … S 3.38-3.39 A ˚, C … C 3.35 A ˚) consistent with electron coupling. Each dimer is surrounded by four I 3 2 anions. The crystal structure of 16 z? I 3 2 is comprised of layers with interplanar separations of 3.55 A ˚. Cations of one layer overlap with anions of the next, and the packing can be described as mixed stacks parallel to the a axis. The remarkably high conductivity of this salt for a system of 1 : 1 stoichiometry (s rt ~8610 22 S cm 21 ) is ascribed to partial charge transfer (the charge on the TTF moiety is estimated as z 2 3 from bond length analysis) and a continuous system of short non-bonding contacts.

Electron donor−π−acceptor chromophores 5, 9, 11, 18−20, 21, 22, 27, 28a, 28c, 31, 32, 34−36, 38a−c, 41a, 41c, and 42 have been synthesised. The donor units are 1,3-dithiole and ferrocene; conjugated ethylenic, phenyl, phenylenevinylene, thienyl, bithienyl, terthienyl, or thienylenevinylene linkers act as a central π-electron relay unit, and dicyanomethylene and polynitrofluorene groups as the acceptor unit. The electronic absorption spectra display a broad low-energy intramolecular charge transfer band in the visible region (500−700 nm) the energy (hν ICT ഠ 1.7−2.5 eV) and intensity (ε ഠ 5000−50000 m −1 cm −1 ) of which depend substantially on the nature of both D and A moieties and on the structure of the linker unit. Nonlinear optical properties have been evaluated using the EFISH technique: the highest µβ (0) values are observed for 38b [(900±300)×10 −48 esu] and 42

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The synthesis of a derivatised cellulose bead with a high loading of primary amines is reported. This material has proved applicable to the removal of excess electrophiles commonly encountered in solution-phase combinatorial chemistry from organic solvents, thus facilitating a rapid purification method of the desired target. The application of the resin to the preparation of an amide and a urea utilising such methodology is presented, along with data on the biodegradation of the resins using enzymatic approaches. The results indicate that the resin behaves in an identical manner to the more traditionally employed polystyrene/divinylbenzene gels often employed in this field, and yet can be prepared from a renewable resource, and biodegraded after use.

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