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6,7-Bis(hexylthio)-2-[(2-hydroxyethyl)thio]-3-methylthio-tetrathiafulvalene (TTF-2) is coupled with thiophene-3-carboxylic acid and thiophene-3,4-dicarboxylic acid by Steglich esterification, respectively, to afford 2-((4′,5′-bis(hexylthio)-5-(methylthio)-[2,2′-bi(1,3-dithiolylidene)]-4-yl)thio)ethyl thiophene-3-carboxylate (TTF-Th) and bis(2-((4′,5′-bis(hexylthio)-5-(methylthio)-[2,2′-bi(1,3-dithiolylidene)]-4-yl)thio)ethyl)thiophene-3,4-di-carboxylate (DTTF-Th). Their structures were characterized by ESI-MS, 1H NMR, and elemental analysis. Electropolymerization of TTF-Th and DTTF-Th was conducted with 0.1 M n-Bu4NPF6. The results indicated that both assemblies could rapidly form polymers via electrochemical deposition. In addition, their electrochromic performances illustrated that the color of P(TTF-Th) could switch from orange-yellow to dark blue, while P(DTTF-Th) changed its color from orange in the neutral state to dark blue in the oxidation state. Moreover, the electrochromic performances of P(DTTF-Th) were better than P(TTF-Th) due to the introduction of one extra TTF unit.

Sulfur-based heterocycles were one of appealing building blocks in functional materials, due to their outstanding optical/electronical performance. Assembled DTTF-BTh which combined from two different sulfur heterocycles was synthesized by condensation of 2-cyanoethylthio-3-methylthio-6, 7-bis (hexylthio) tetrathiafulvalene ( TTF-1), and 4, 4′-bis (2′-bromoethoxy)- 3, 3′-bithiophene ( DBE-BTh). The full structural and physical characterizations of novel DTTF-BTh were studied by H NMR, Mass, UV-Vis absorption, and electrochemical measurements. The two heterocycle moieties were connected successfully but inclined to perform individually. This could be explained as electron separation by alkyl chains. Electropolymerization was also conducted. The result indicated that DTTF-BTh could directly form polymeric films on prepared ITO glass via electrochemical deposition. Moreover, the deposited polymer film possessed an electrochromic performance. [ABSTRACT FROM AUTHOR]

3,4-(Hydroxymethyl-ethylenedioxy)thiophene ( 4) and 3,4-(2′-hydroxypropylenedioxy)thiophene ( 4'′) were synthesized from dimethyl 3,4-dihydroxythiophene-2,5-dicarboxylate ( 1), which were isomers and difficult to separate. When they were esterified with tetrathiafulvalene carried carboxylic acid group, only 3,4-(hydroxymethyl-ethylenedioxy)thiophene ( 4) could be esterified. No such selectivity was observed when the isomers were esterified by lauric acid and benzoic acid, respectively. [ABSTRACT FROM AUTHOR]

Three 3,4-ethylenedioxythiophene (EDOT) derivatives, including an EDOT-tetrathiafulvalene (TTF) derivative, were synthesized by Steglich esterification of carboxylic acids with hydroxymethyl EDOT (3,4-ethylenedioxythiophene methanol). The UV spectra showed that there was no distinctive intramolecular interaction for the EDOT-TTF monomer between the EDOT and the TTF moieties in the ground state; however, the cyclic voltammetry responses implied that such intramolecular interaction occurred. Electropolymerization in excessive potential could bring in strong overoxidation effects and degradation in the polymer film. The polymers were simulated using density functional theory with Gaussian03 package and the optimized HOMO and LUMO state were figured out. The conductivity of TTF-polymer was 6 S·cm−1 obtained by galvano station and 4.8 × 10−3 S·cm−1 obtained by potentiostatic electropolymerization after doping with 7,7,8,8-tetracyanoquinodimethane. The results indicated that this polymer was a reasonable candidate for conducting materials and it was meaningful to increase the conductive dimensions of TTF polymers by chemical doping. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

A kind of π-conjugated poly(EDOT-ethynylene-arylene)s P1- P5 were synthesized by Sonogashira coupling reaction between DBEDOT and five arylenes substituted with ethynyl groups. Among them, P5 was a polymer with TTF as pendants. Their TGA results exhibited their good thermal stability and their electrochemical and spectroscopic properties were investigated by CV, UV-Vis, and FL. The results indicated that there were intramolecular interactions between TTF group and polymer backbone as well as between the EDOT and arylene moieties. After doping with TCNQ, P5 could form stable CT-complex with a conductivity of 1.3 × 10 S cm, while its conductivity could be up to 3.5 × 10S cm after doping with I, due to its increased conductive dimensions. Such results indicated that this polymer had potential application in developing conducting materials. Graphical Abstract: A kind of π-conjugated EDOT-ethynylene-fluorene polymer with TTF as pendants was synthesized, which exhibited good solubility and thermal stability. When doping with I, its conductivity was improved significantly due to its increased conductive dimensions.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A series of conjugated ethynylene-fluorene polymers with electro-donating TTFas pendant groups (P2–P4) were synthesized by using Sonogashira coupling reaction, and two functionalization methods, i.e.prepolymerization and postpolymerization, were developed. The composition and purity of the corresponding products were analyzed by 1H NMR. The results proved the functionalization of P2(pre) and P2(post) were 40% and 100%, respectively. The results also indicated that the postpolymerization method would be a better approach to prepare TTF-pendant conjugated ethynylene-fluorene polymers. The postpolymerization methodology could be extended to synthesize other conjugated fluorene-based polymers bearing TTFunits (P3and P4). The polymers mentioned above exhibited good solubility in normal organic solvents and higher conductivity (neutral conductivity ∼2–4 × 10−6S cm−1; doped conductivity ∼1–3 × 10−3S cm−1). Moreover, the fluorescence intensity of P2(post) could be modulated by the oxidation of TTFunits, which makes it an attractive candidate for the fluorescence switch. [ABSTRACT FROM AUTHOR]

Abstract: Two tetrathiafulvalene (TTF)-derived metallophthalocyanine complexes were synthesized. The structures of the target compounds and their intermediates have been characterized by NMR, MS, EA, UV–VIS and mp. The results of cyclic voltammetry indicated that the presence of zinc or magnesium phthalocyanine slightly affected the first oxidation of 4,5-ethylenedithiotetrathiafulvalene (EDT-TTF) unit. The EDT-TTF unit on the peripheral sites of the zinc phthalocyanine core could be more easily oxidized than the one on the same sites of the magnesium phthalocyanine core. [Copyright &y& Elsevier]

A new dual chemosensor ( TTF-PBA ) for Fe 3+ and Cu 2+ in different signal pathways was designed and synthesized. The absorption spectrum, fluorescence spectrum and cyclic voltammograms changed in the presence of Cu 2+ and Fe 3+ . The optical color changed within 5 s from yellow to orange upon the addition of Cu 2+ , and it changed to dark yellow when Fe 3+ existed. The cyclic voltammogram of Cu 2+ /TTF-PBA changed from E ox = 0.50 V, E red = 0.32 V to E ox = 0.64 V, E red = 0.80 V ( vs Ag/AgCl) upon the addition of 2.0 equiv. Cu 2+ . As for Fe 3+ /TTF-PBA, its oxidation wave disappeared, and its reduction wave appeared at E red = −0.59 V ( vs Ag/AgCl) upon the addition of 4.0 equv. Fe 3+ . The sensor displayed high selectivity for Cu 2+ and Fe 3+ over other ions including Pb 2+ , Zn 2+ , Ni 2+ , Ag + , Cr 3+ , Mn 2+ , Al 3+ , Co 2+ , Pd 2+ , Hg 2+ , Fe 2+, Cd 2+ , Ce 3+ , Bi 3+ and Au 3+ , the detection limits for Cu 2+ and Fe 3+ ion reached as low as 5.33 × 10 −7 mol/L and 5.34 × 10 −7 mol/L, respectively. Furthermore, when Fe 3+ existed, Cu 2+ can be detected sequentially by the sensor through the absorption spectrum and the color change observed by naked-eyes. [ABSTRACT FROM AUTHOR]

Monomer 5 was designed and synthesized via Steglich esterification reaction by connecting 3, 4-propylenedioxythiophene methanol (2) and derivative of tetrathiafulvalene (3). The structure was characterized by EI-MS, 1 H NMR and elemental analysis. Its behavior and performance were studied via comparison to monomer 4. The result indicated that the intramolecular charge transfer of 5 was greatly inhibited due to the broadened band gap as well as the twisted plane of the molecule. [ABSTRACT FROM AUTHOR]

Two novel donor-π-acceptor chemosensors, exTTF-DPA and exTTF-ADPA, based on π-extended tetrathiafulvalene (exTTF) and di(pyridine-2-ylmethyl)amine (DPA) were synthesized and used as optical and electrochemical chemosensors for copper(II). The results showed that they possess specific selectivity for copper(II) in the presence of other competing metal ions (Zn 2+ , Sn 2+ , Pb 2+ , Pd 2+ , Hg 2+ , Al 3+ , Fe 3+ , Ag + , Co 2+ , Ni 2+ ) in acetonitrile. Upon the addition of Cu 2+ , the solution color changed from yellow to orange, the cyclic voltammograms changed dramatically and the fluorescence quenched completely. [ABSTRACT FROM AUTHOR]

Abstract: Two donor-σ-acceptor-σ-donor triads incorporating tetrathiafulvalene (TTF) and 3,4,9,10-perylene tetracarboxylic diimides (PDI) units were synthesized. The structures of the triads and their intermediates were characterized by 1H NMR, 13C NMR, MS, IR. The results of UV–vis and cyclic voltammetry (CV) of the triads indicated negligible intramolecular charge transfer (ICT) interaction in their ground states. The fluorescence and fluorescence lifetimes of the triads were reduced compared to PDIs, which evidently indicated that photoinduced electron transfer (PET) interaction occurred from the TTF unit to the PDI unit in the excited state. The fluorescence intensity of the triads could be reversibly modulated by sequential oxidation and reduction of the TTF unit using the chemical methods. Therefore two new fluorescence molecular switches based on TTF and PDI units were established. [Copyright &y& Elsevier]