Jan Becher

A mono-TTF-annulated porphyrin as a fluorescence switchElectronic supplementary information (ESI) available: data for 4. See http://www.rsc.org/suppdata/cc/b2/b212456d/

Annulation of one TTF unit directly to the porphyrin chromophore produces an almost nonfluorescent species which can be transformed into a fluorescent species by oxidation of the TTF unit.

Formation of oriented molecular nanowires on mica surface

Molecular “nanowire” structures composed of the charge transfer complex of a bis-tetrathiafulvalene substituted macrocycle and tetrafluorotetracyanoquinodimethane were constructed on mica substrates by employing the Langmuir–Blodgett technique. The nanowires transferred from a dilute aqueous potassium chloride subphase had typical dimensions of 2.5 nm × 50 nm × 1 μm. The nanowires are oriented to specific directions, corresponding to the directions of the potassium-ion array on the mica surface having sixfold symmetry. Such correlation between the nanowires and the substrate surface was also observed when a dilute aqueous rubidium chloride subphase was used. On the other hand, the correlation completely disappeared when the subphase contained divalent cations, indicating that the molecular nanowires orient by recognizing the monocation array on the mica surface. The nanowires formed by the vertical dipping method coexist with the monolayers. Only nanowire structures are, however, observed when we apply the horizontal lifting method. Based on the crystal structure of a related complex, a possible structure of the nanowires is presented. The conductivity of the nanowires was estimated to be of the order of 10−3 S⋅cm−1. The nanowires formed specific (regular) structures such as T-shape junctions, suggesting their use in construction of future molecular nanoscale devices.

Tetrathiafulvalenes: from heterocyclic chemistry to molecular devices

Abstract This account highlight recent developments in the field of supramolecular tetrathiafulvalene (TTF) chemistry. Progress in synthetic TTF chemistry has enabled the preparation of elaborate molecular systems and architectures. System based on host–guest interactions may act as, for example, sensors or molecular switches. Among these systems mechanically interlocked architectures such as catenanes and rotaxanes are now prime candidates for the construction of artificial molecular machines and the fabrication of molecular electronic devices.

Tetrathiafulvalenophanes and theircatenanes

Monomacrocycles of the two electron donors tetrathiafulvalene (TTF) and 1,5-dioxynaphthalene have been prepared, together with three symmetric TTF-containing bismacrocycles, two of which have been prepared by a two-step deprotection–cyclization approach. By utilizing the donor–acceptor interactions of these donors with the dipyridinium dication of 1,1′-[1,4-phenylenebis(methylene)]bis-4,4′-bipyri dinium bis(hexafluorophosphate), [2]catenanes were synthesized. In the case of one of the bismacrocycles it was possible to isolate a minor amount of a bis[2]catenane. The catenanes were characterized by 1 H NMR spectroscopy, electrospray mass spectroscopy (ESMS) and their fragmentation in the gas phase was also analysed by collisional activation (ESMS/MS). Also, one tetramacrocyclic compound, the first TTF-based ribbon compound, has been synthesized. This compound shows complex electrochemical properties.

A copper(I) [2]-catenate incorporating a tetrathiafulvalene unit

Abstract A copper(I) [2]-catenate incorporating an electron-donor tetrathiafulvalene unit has been synthesized and characterized.

Synthesis and non-linear optical properties of mono-pyrrolotetrathiafulvalene derived donor–π–acceptor dyads

The synthesis of novel donor–π–acceptor dyads based on a pyrrolo-annelated tetrathiafulvalene unit is described. The linear and non-linear optical properties of these chromophores have been investigated, together with their redox properties. For a dyad containing a p-nitrophenyl acceptor group, a significant third-order optical non-linearity is observed.

The synthesis of 4,4'(5')-diformyltetrathiafulvalene

The synthesis of the title compound 9, by three different routes, is described for the first time.

Caesium tetrathiafulvalene-thiolates: key synthetic intermediates

Treatment of cyanoethylated tetrathiafulvalene-thiolates or cyanoethylated 1,3-dithiole-2-thione-4,5-dithiolate with one equiv. of caesium hydroxide hydrate selectively and in high yield produces the corresponding monocaesium salts, which can subsequently be alkylated.

Divalent transition metal complexes of alkylpyridyl derivatized dmit ligands

Abstract The two new bis-alkylpyridyl substituted dmit ligands, 4,5-bis(2-pyridylmethylsulfanyl)-1,3-dithiole-2-thione (bpmdmit) and 4,5-bis(2-pyridylethylsulfanyl)-1,3-dithiole-2-thione (bpedmit), and some of their transition metal complexes have been prepared. Two basic structural types for the complexes MX2L (M=Ni, Co, Cu, Pd; L=bpmdmit or bpedmit; X=Cl or Br) were determined by X-ray crystallography. The cobalt(II) and the nickel(II) complexes CoBr2(bpmdmit) and NiCl2(bpmdmit) show octahedral geometries around the metal ions with coordination to the metal ions by the pyridyl nitrogen atoms and the thioether sulfur atoms of the ligand and cis coordination of the halide ions. By contrast, only the pyridyl nitrogen atom of the ligands in the copper(II) and the palladium(II) complexes, CuCl2(bpedmit) and PdCl2(bpedmit), are coordinated to the metal ions to give essentially square planar metal environments. The copper complex was isolated as both green and purple crystals. However, the X-ray structures of both forms are similar, and show a dimeric arrangement with bis-μ-chloride bridges between the copper ions in the dimeric units. The green crystals contain two molecules of acetonitrile in the unit cell, however these do not interact with the metal ions. The geometry of the copper ions in the green form deviates most from centrosymmetric square planar geometry and this is consistent with the observed colour. Apart from the colour, the solids can be distinguished in the solid state by EPR spectroscopy since they give different rhombic signals. UV–Vis and EPR spectroscopy show that in solution the structures of the purple and green forms of CuCl2(bpedmit) are identical, as expected.

Functionalised tetrathiafulvalene (TTF) systems derived from 4,5-(propylenedithio)-1,3-dithiole units

Abstract A range of functionalised symmetrical and unsymmetrical tetrathiafulvalene (TTF) derivatives containing substituted 4,5-(propylenedithio)-1,3-dithiole units has been prepared. Key half-units are the t-butyldiphenylsilyl-protected 1,3-dithiole derivative 18 and the ketal-protected derivative 32. Self-coupling and cross-coupling reactions of these half-units, with 1,3-dithiole-2-one and -2-thione derivatives 19–22 occurs in the presence of triethylphosphite. After deprotection, TTF derivatives 14, 24, 28, 34 and 40–43, bearing hydroxy or ketone functionality are obtained. Functionalisation of the alcohol group(s) of 14, 24 and 28 has been achieved with acid chlorides and with isocyanates, to give compounds 16, 17, 25, 26 and 29. Cyclic voltammetric studies establish that the new TTF derivatives are efficient π-electron donors; they undergo two reversible, single-electron redox waves. The X-ray crystal structures of 4,5-(2-hydroxypropylenedithio)-1,3-dithiole-2-thione 3 and the ketal-prote