Ahmed Belyasmine

Extended analogues of tetrathiafulvalene (TTF): 1,2-bis, 1,4-bis and 1,2,4,5-tetrakis(1,4-dithiafulven-6-yl) benzenes; Synthesis and π-donor abilities.

Abstract The title compounds are prepared by Wittig or Wittig-Horner reactions between the corresponding benzenes di- and tetracarbaldehydes and the P-reagents W or P bearing the 1,3-dithiol-2-ylidene moiety; among them, the tetrakis(dithiafulvenyl)benzene 3c is shown by cyclic voltammetry to possess the best π-donor character and, also, is chemically or electrochemically oxidized.

A self-assembled bis(pyrrolo)tetrathiafulvalene-based redox active square

The synthesis and full characterization of a redox-active π-donating molecular square is described, through coordination-driven self-assembly of a new key bis(pyrrolo)TTF building block with Pt(II) salts; the electrochemical behaviour of the square is consistent with noninteracting bis(pyrrolo)TTF units.

N-Aryl Pyrrolo-tetrathiafulvalene Based Ligands: Synthesis and Metal Coordination

A straightforward general synthetic access to N-aryl-1,3-dithiolo[4,5-c]pyrrole-2-thione derivatives 6 from acetylenedicarbaldehyde monoacetal is depicted. In addition to their potentiality as precursors to dithioalkyl-pyrrole derivatives, thiones 6 are key building blocks to N-aryl monopyrrolo-tetrathiafulvalene (MPTTF) derivatives 10. X-ray structures of four of these thiones intermediates, reminiscent of the corresponding MPTTF derivatives, are provided. When the aryl group is a binding pyridyl unit, the MPTTF derivative 10a can coordinate M(II) salts (M = Pt, Pd). The first examples of metal-directed orthogonal MPTTF-based dimers 11-14, obtained through coordination of 10a to cis-blocked square planar Pt or Pd complexes are described. Studies on the parameters influencing the dimer construction are presented, as well as first recognition properties of the resulting electron-rich clip for C(60).

Acid mediated intramolecular cyclization of π-donors bearing two vicinal “cis”-branched, 1,4-dithiafulven-6-yl substituents on a CC bond

Abstract Cis-ethylenic analogues 1 and ortho-benzenic analogues 2 of TTF undergo a rapid acid mediated intrmolecular cyclization into two the corresponding cycloisomers 1′ and 2′ whose structures are confirmed by X-ray diffraction; as shown by cyclic Voltammetry, compounds 1 may act as convenient precursors of organic metals.

Vinylogs of tetrathiafulvalene (TTF) bearing four 1,4-dithiafulven-6-yl substituents : Novel highly extended and sulfur-rich π-donors

Abstract The title compounds 1 were synthesized from the mono-diEt-acetal of acetyleneddicarbaldehyde and 2-thioxo-1,3- dithioles through three key steps: cycloaddition, dimerization-desulphurization of the resulting thials, and after deketalization, fourfold Wittig olefination of the tetraformyl TTF-vinylogs 4 with the P-ylids Wα-γ bearing the 1,3-dithiol-2-ylidene moiety. Cyclic voltammetry shows that these compounds are very strong π-donors and good precursors of conducting cation-radical salts.

Cycloaddition of 3-thioxo-12-dithioles onto acetylenedicarbaldehyde and its mono-diethylacetal : Ready access to intermediates in the tetrathiafulvalene (TTF) series

Abstract The 4,5-diformyl-1,3-dithiol-2-ylidene ethanals and ethanones 4 are prepared by a three-step sequence from acetylenedicarbaldehyde mono-diEt-acetal and 3-thioxo-1,2-dithioles. Their X-ray diffraction structure, 1H nmr and IR properties, reveal a δ-cis conformation in the solid state and in solution, due to strong S…O 1,5-internal bonding interactions.

Polyacetyl-substituted tetrathiafulvalenes and 1,3-dithiolic derivatives from hex-3-yn-2,5-dione

Abstract The cycloaddition of hex-3-yn-2,5-dione onto a π-CS 2 Iron complex 3 and on 3-thioxo 1,2-dithioles affords diacetylated intermediates which can be readily converted into di or tetraacetylated derivatives of the 1,3-dithiole (5,6) and tetrathiafulvalene (2,8) series, some representative electrochemical and structural features of which being also presented.

A new generation of giant analogs of tetrathiafulvalene (TTF): Vinylogs of TTF bearing four 1,4-dithiafulvalenyl substituents

Abstract A straightforward synthesis of the new title compounds 5 is presented which involves, as the final step, four-fold Wittig or Wittig-Horner reactions of the corresponding tetraaldehydes with the P-reagents W or P bearing the 1,3-dithiole-2-ylidene moiety; the good π-donor ability of 5 is provided by cyclic voltammetry.

Bis and tetrakis(6-methyl-1,4-dithiafulven-6-yl) substituted tetrathiafulvalenes (TTF) and their vinylogs as novel π-donors

Abstract The synthesis of highly extended and sulfur rich tetrathiafulvalene derivatives, designed to avoid any internal cyclisation during their subsequent electrooxidation, is described. Their π-donating ability is confirmed by cyclic voltammetry, as well as the good stability of each of their oxidized species (up to an hexacationic state in one case).

New Derivatives of Tetrathiafulvalenes (TTF): Towards Organic Metals of Enhanced Dimensionality

Abstract In order to get π-donors prone to develop organic metals of enhanced dimensionality (> lD), the TTF or TSF derivatives 1-4 bearing two or four 1,4-dithiafulven-6-yl substituents adequately R-substituted have been synthesized. Usual and thin layer cyclic voltammetries evidence their tremendous π-donor ability and also the various stoichiometries of the salts produced upon their oxidation. Among them, X ray structure of [2 (saturated, R[dbnd]H)]1 (ClO4)1 exhibits an unusual 2-D network and behaves as a semiconductor of uncommon high conductivity (close to 1 S.cm−1 at r.t.). This property is indicative of weak Coulombic repulsions as well as strong interactions between the oxidized donors. By changing the R-substituents of 2 we have recently obtained a (2)2(anion)1 salt endowed with a 2D character.