Ronald L. Meline

A convenient non-coupling synthesis of bis(ethylenedithio)tetrathiafulvalene

Abstract A new synthesis of bis(ethylenedithio)tetrathiafulvalene ( 5 ; BEDT-TTF) has been developed by an unusual route. 4,5-Bis(benzoylthio)-1,3-dithiole-2-thione ( 1 ) or commercially available 1,3,4,6-tetrathiapentalene-2,5-dione ( 2 ; thiapendione) is directly converted with sodium ethoxide and cis-1,2-dichloroethylene into 1,4,5,8-tetrathianaphthalene ( 3 ; TTN; 1,4,5,8-tetrathiatetralin) in high yield. TTN is then tetralithiated with an excess of lithium diisopropylamide in tetrahydrofuran, and sulfur is inserted into the four carbonlithium ion pairs. Subsequent capping on both ends of the reactive intermediate with 1,2-dibromoethane leads to an appreciable yield of BEDT-TTF after recrystallization. The reaction takes advantage of a smooth intramolecular rearrangement of the tetralithiated TTN intermediate. BEDT-TTF is confirmed by 1 H-NMR, IR and mass spectroscopy, and is characterized by solution 13 C-NMR.

Electric birefringence of surfactant vesicles

Abstract Transient electric birefringence is induced by single, high-voltage electric square pulses in isotropic aqueous suspensions of unilamellar bilayer vesicles (liposomes) prepared from the surfactants egg L-α-phosphatidylcholine (EPC) or dioleoylphosphatidylcholine (DOPC). Preliminary results for DOPC vesicles are presented on the effects of concentration, temperature, and electric field strength on the steady-state induced optical retardation δo. Within the ranges investigated, the positive δo is relatively insensitive to change in temperature, but depends on the other variables. Possible mechanisms of the induction of birefringence are discussed.

The tuning of heterocyclic isomerization : Additional routes to extended donors

Tetrathianaphthalene: A precursor easily synthesized in bulk, is utilized in the synthesis of tetrathiafulvalene, and extended chalcogenated tetrathianaphthalenes and tetrathiafulvalenes. The donor syntheses dependant upon core heterocycle configuration retention or isomerization are controlled via the use of novel solvent systems and new classes of disulfide building blocks.

Synthesis and electrochemical properties of bis(3,4-furyldimethylthio)tetrathiafulvalene and other tetrathiafulvalene donors with eight-membered heterocycles

Abstract Bis(3,4-furyldimethylthio)tetrathiafulvalene, bis(but-2-ene-1,4-dithio)tetrathiafulvalene and bis(2,3-dimethylbut-2-ene-1,4-dithio)-tetrathiafulvalene are synthesized in high yield from tetrakis(cyanoethylthio)tetrathiafulvalene and primary alkyl halides. Electrochemical properties are compared and the new donors are related to analogous quasi-one-dimensional organic metals.

Poly(3-alkylthiophenes): Optimising conductivity as a function of regioregularity, dopant and casting solvent

Thiophene and 3-methylthiophene as casting solvents are shown to improve the conductivity of cast films of regioregular and regiorandom poly(3-octylthiophenes). The trend is observed from same batch samples using different dopants.

An expedient, cost effective large scale synthesis of tetrathiafulvalene

TTF is synthesized (85% yield) in two steps from 4,5-bis(benzoylthio)-1,3-dithiole-2-thione and isolated in high purity without the use of chromatography.

Organic Metals and Superconductors: Facile Synthetic Methodologies Bypassing Coupling and Chromatography

The organic donor tetrathiafulvalene (TTF, 1) and its derivatives are synthesized from tetrathianaphthalene (TTN, 2) in a one pot reaction. The reaction takes advantage of an isomerization of lithiated TTN into lithiated TTF and subsequent substitution with novel disulfide electrophiles yielding substituted T donors. The isomerization approach eliminates the need for a chemical coupling reaction of oxones or thiones (a yield limiting procedure), and simple byproducts eliminate the need for tedious purification. The novel methodology allows for a high yield preparation of bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF, 3a, 80%) and bis(propylenedithio)tetrathiafulvalene (BPDT-TTF, 3b), previously unavailable directly from TTF. A high yield of bis(phenylenedithio)tetrathiafulvalene (BPhDT-TTF, 3c, unavailable from dimercaptoisotrithione “DMIT”) is also achieved using the synthetic scheme. The method is general, and can be used to prepare a variety of novel organic donors based on TTF. Synthetic procedures along with all relevant characterization are presented.