2,4-Dichloro-6-({2-[(3,5-dichloro-2-hy­droxy­benzyl­idene)amino]­eth­yl}imino­meth­yl)phenol

The title mol­ecule, C16H12Cl4N2O2, lies about an inversion center. The symmetry-unique part of the mol­ecule contains an intra­molecular O—H⋯N hydrogen bond. In the crystal, mol­ecules are arranged in corrugated layers parallel to (-101). Weak π–π stacking inter­actions, with a centroid–centroid diatance of 3.7923 (13) Å, are present

Bis(3-acetyl-6-methyl-2-oxo-2H-pyran-4-olato)bis­(dimethyl sulfoxide)nickel(II)

In the title compound, [Ni(C8H7O4)2{(CH3)2SO}2], the NiII atom is located on a crystallographic centre of symmetry and has a distorted octa­hedral coordination geometry of type MO6. The bidentate dehydro­acetic acid (DHA) ligands occupy the equatorial plane of the complex in a trans configuration, and the dimethyl sulfoxide (DMSO) ligands are weakly coordinated through their O atoms in the axial positions

2-[N-(4-{4-[(2-Hy­droxy-5-meth­oxy­benzyl­idene)amino]­benz­yl}phen­yl)carboximido­yl]-4-meth­oxy­phenol

In the title Schiff base, C29H26N2O4, the complete molecule is generated by a crystallographic twofold axis and is V-shaped. The planes of the benzene rings of the central diphenyl­methane unit make a dihedral angle of 78.11 (4)° while adjacent benzene and 5-meth­oxy­salicyl­idene rings are twisted with respect to each other by a dihedral angle of 11.84 (8)°. The Schiff base is in the enol–imino form and an intra­molecular O—H⋯N hydrogen bond is observed

Combining chirality and hydrogen bonding in methylated ethylenedithio- tetrathiafulvalene primary diamide precursors and radical cation salts

Methyl- and dimethyl-ethylenedithio-tetrathiafulvalene ortho-diamide donors Me-EDT-TTF(CONH2)2 (1a) and DM-EDT- TTF(CONH2)2 (1b) have been prepared by the direct reaction of the corresponding diester precursors with aqueous ammonia solutions. The neutral (rac)-1a, (R)-1a, and (S,S)-1b donors have been characterized by single crystal X-ray diffraction. In the three compounds, which crystallized in the non-centrosymmetric monoclinic space group P21, the amide groups are disordered, yet they form the classical intra-molecular hydrogen bond for such an ortho-diamide motif. Electro- crystallization experiments afforded the mixed valence radical cation salts[(S,S)-1b]2XO4 and [(R,R)-1b]2XO4 (X = Cl, Re) containing four independent donors in the asymmetric unit, with the positive charge localized essentially on two donors, while the two others are neutral. The topology of the organic layer is of β′-type. Single crystal resistivity measurements show semiconducting behavior for [(S,S)-1b]2ClO4 and [(R,R)-1b]2ReO4, with a room temperature conductivity of 5 × 10−5 S cm−1 and activation energies Ea ≈ 3000 K. Tight-binding band structure calculations of extended Hückel type in combination with density functional theory calculations are in agreement with the semiconducting behavior and suggest a localized Mott type semiconductor rather than a band gap semiconductor

O-Doped Nanographenes: A Pyrano/Pyrylium Route Towards Semiconducting Cationic Mixed-Valence Complexes

Herein we report an efficient synthesis to prepare O-doped nanographenes derived from the π-extension of pyrene. The derivatives are highly fluorescent and feature low oxidation potentials. Using electrooxidation, crystals of cationic mixed-valence (MV) complexes were grown in which the organic salts organize into face-to-face π-stacks, a favorable solid-state arrangement for organic electronics. Variable-temperature electron paramagnetic resonance (EPR) measurements and relaxation studies suggest a strong electron delocalization along the longitudinal axis of the columnar π-stacking architectures. Electric measurements of single crystals of the MV salts show a semiconducting behavior with a remarkably high conductivity at room temperature. These findings support the notion that π-extension of heteroatom-doped polycyclic aromatic hydrocarbons is an attractive approach to fabricate nanographenes with a broad spectrum of semiconducting properties and high charge mobilities

A bridged low band gap A-D-A quaterthiophene as efficient donor for organic solar cells

International audience[small alpha],[small omega]-Bis(dicyanovinyl)quaterthiophene 1 with a median 4,4-diethyl-4H-cyclopenta[2,1-b:3,4-b[prime or minute]]dithiophene has been synthesized. UV-Vis absorption data show that the covalent bridging of the inner 2,2[prime or minute]-bithiophene leads to a significant reduction of the HOMO-LUMO gap essentially due to an increase of the HOMO level as confirmed by electrochemical and theoretical results. X-ray diffraction analysis of a single crystal of 1 shows that except for the out-of-plane ethyl groups, the conjugated system displays a quasi-planar geometry while the molecular packing exhibits strong [small pi]-stacking interactions and multiple short intermolecular contacts. Quaterthiophene 1 has been used as active donor material in organic solar cells of various architectures including bi-layer planar hetero-junctions and hybrid co-evaporated bulk hetero-junctions with C60 as electron acceptor material. A maximum conversion efficiency of 4.30% is obtained with a hybrid co-evaporated device. These results are discussed in terms of structure-properties relationships with reference to the open-chain parent [small alpha],[small omega]-bis(dicyanovinyl)quaterthiophene 2

Triphenylamine/Tetracyanobutadiene-Based π-Conjugated Push–Pull Molecules End-Capped with Arene Platforms:Synthesis, Photophysics, and Photovoltaic Response

π-Conjugated push–pull molecules based on triphenylamine and 1,1,4,4-tetracyanobuta-1,3-diene (TCBD) have been functionalized with different terminal arene units. In solution, these highly TCBD-twisted systems showed a strong internal charge transfer band in the visible spectrum and no detectable photoluminescence (PL). Photophysical and theoretical investigations revealed very short singlet excited state deactivation time of ≈10 ps resulting from significant conformational changes of the TCBD-arene moiety upon photoexcitation, opening a pathway for non-radiative decay. The PL was recovered in vacuum-processed films or when the molecules were dispersed in a PMMA matrix leading to a significant increase of the excited state deactivation time. As shown by cyclic voltammetry, these molecules can act as electron donors compared to C 60. Hence, vacuum-processed planar heterojunction organic solar cells were fabricated leading to a maximum power conversion efficiency of ca. 1.9 % which decreases with the increase of the arene size

Études structurales par diffraction des rayons X appliquées à des cages supramoléculaires et à des conducteurs moléculaires

The discrete self-assembled metal assisted structures are big size edifices which do not crystallize easily and decompose rapidly. Moreover, the resolution of these structures is difficult because of the medium quality of the diffraction data sets. Different crystals selection techniques and a refinement method, applied to the supramolecular cages, are discussed, with a particular focus on the use of the Squeeze program which allows the suppression of the disordered atoms and molecules contributions. Two types of isolated and interlocked cages are structurally described. In the second part, a series of new organic conducting materials based on TMTSF and on TTF derivatives, incorporating a novel fluoro-tantalate anion, is described. The structure-conducting properties relationship is discussed. The first Bechgaard phase with a magnetic anion, namely hexafluororhenate, is described, together with its temperature dependent stability and conducting properties. TMTSF and BEDT-TTF have been associated to several mixed tantalum, rhenium or phosphorous hexafluoro anions to provide new conducting alloys. These syntheses also afforded crystalline materials with original anions. Two methods to estimate the oxydation state of the TMTSF donors are compared for several radical cation salts, either prepared during this PhD work or selected from a crystallographic data base.Les structures discrètes auto-assemblées dirigées par les métaux sont des édifices de grande taille qui cristallisent difficilement et se décomposent rapidement. De plus, la résolution de ces structures est compliquée par des données de diffraction de moyenne qualité. Différentes techniques de sélection de cristaux et une méthode d’affinement de structure, appliquée aux cages, sont discutées avec notamment l’utilisation détaillée du programme Squeeze qui permet de supprimer la contribution des atomes et molécules désordonnés ou non visibles dans ces grandes structures. Deux types de cages isolées et entrelacées sont décrites structuralement. Dans la deuxième partie, une série de nouveaux matériaux conducteurs organiques à base de TMTSF et de dérivés du TTF, et incorporant un nouvel anion fluorotantalate, est décrite et les relations structure-propriétés de conduction sont discutées. La première phase de Bechgaard avec l’anion magnétique hexafluoro-rhénate a été caractérisée et différentes études de stabilité en température et de conduction sont présentées. Le TMTSF et le BEDT-TTF ont été associés à plusieurs anions mixtes hexafluorés de tantale, de rhénium et de phosphore pour former de nouveaux alliages conducteurs. Ces synthèses ont également générées des matériaux avec des anions originaux. Deux méthodes de détermination de la charge sur les TMTSF ont été comparées sur plusieurs conducteurs organiques, issus de ce travail ou d’une base de données cristallographiques

X-Ray diffraction structural studies applied to supramolecular cages and molecular conductors

Les structures discrètes auto-assemblées dirigées par les métaux sont des édifices de grande taille qui cristallisent difficilement et se décomposent rapidement. De plus, la résolution de ces structures est compliquée par des données de diffraction de moyenne qualité. Différentes techniques de sélection de cristaux et une méthode d’affinement de structure, appliquée aux cages, sont discutées avec notamment l’utilisation détaillée du programme Squeeze qui permet de supprimer la contribution des atomes et molécules désordonnés ou non visibles dans ces grandes structures. Deux types de cages isolées et entrelacées sont décrites structuralement. Dans la deuxième partie, une série de nouveaux matériaux conducteurs organiques à base de TMTSF et de dérivés du TTF, et incorporant un nouvel anion fluorotantalate, est décrite et les relations structure-propriétés de conduction sont discutées. La première phase de Bechgaard avec l’anion magnétique hexafluoro-rhénate a été caractérisée et différentes études de stabilité en température et de conduction sont présentées. Le TMTSF et le BEDT-TTF ont été associés à plusieurs anions mixtes hexafluorés de tantale, de rhénium et de phosphore pour former de nouveaux alliages conducteurs. Ces synthèses ont également générées des matériaux avec des anions originaux. Deux méthodes de détermination de la charge sur les TMTSF ont été comparées sur plusieurs conducteurs organiques, issus de ce travail ou d’une base de données cristallographiques.The discrete self-assembled metal assisted structures are big size edifices which do not crystallize easily and decompose rapidly. Moreover, the resolution of these structures is difficult because of the medium quality of the diffraction data sets. Different crystals selection techniques and a refinement method, applied to the supramolecular cages, are discussed, with a particular focus on the use of the Squeeze program which allows the suppression of the disordered atoms and molecules contributions. Two types of isolated and interlocked cages are structurally described. In the second part, a series of new organic conducting materials based on TMTSF and on TTF derivatives, incorporating a novel fluoro-tantalate anion, is described. The structure-conducting properties relationship is discussed. The first Bechgaard phase with a magnetic anion, namely hexafluororhenate, is described, together with its temperature dependent stability and conducting properties. TMTSF and BEDT-TTF have been associated to several mixed tantalum, rhenium or phosphorous hexafluoro anions to provide new conducting alloys. These syntheses also afforded crystalline materials with original anions. Two methods to estimate the oxydation state of the TMTSF donors are compared for several radical cation salts, either prepared during this PhD work or selected from a crystallographic data base

Études structurales par diffraction des rayons X appliquées à des cages supramoléculaires et à des conducteurs moléculaires

The discrete self-assembled metal assisted structures are big size edifices which do not crystallize easily and decompose rapidly. Moreover, the resolution of these structures is difficult because of the medium quality of the diffraction data sets. Different crystals selection techniques and a refinement method, applied to the supramolecular cages, are discussed, with a particular focus on the use of the Squeeze program which allows the suppression of the disordered atoms and molecules contributions. Two types of isolated and interlocked cages are structurally described. In the second part, a series of new organic conducting materials based on TMTSF and on TTF derivatives, incorporating a novel fluoro-tantalate anion, is described. The structure-conducting properties relationship is discussed. The first Bechgaard phase with a magnetic anion, namely hexafluororhenate, is described, together with its temperature dependent stability and conducting properties. TMTSF and BEDT-TTF have been associated to several mixed tantalum, rhenium or phosphorous hexafluoro anions to provide new conducting alloys. These syntheses also afforded crystalline materials with original anions. Two methods to estimate the oxydation state of the TMTSF donors are compared for several radical cation salts, either prepared during this PhD work or selected from a crystallographic data base.Les structures discrètes auto-assemblées dirigées par les métaux sont des édifices de grande taille qui cristallisent difficilement et se décomposent rapidement. De plus, la résolution de ces structures est compliquée par des données de diffraction de moyenne qualité. Différentes techniques de sélection de cristaux et une méthode d’affinement de structure, appliquée aux cages, sont discutées avec notamment l’utilisation détaillée du programme Squeeze qui permet de supprimer la contribution des atomes et molécules désordonnés ou non visibles dans ces grandes structures. Deux types de cages isolées et entrelacées sont décrites structuralement. Dans la deuxième partie, une série de nouveaux matériaux conducteurs organiques à base de TMTSF et de dérivés du TTF, et incorporant un nouvel anion fluorotantalate, est décrite et les relations structure-propriétés de conduction sont discutées. La première phase de Bechgaard avec l’anion magnétique hexafluoro-rhénate a été caractérisée et différentes études de stabilité en température et de conduction sont présentées. Le TMTSF et le BEDT-TTF ont été associés à plusieurs anions mixtes hexafluorés de tantale, de rhénium et de phosphore pour former de nouveaux alliages conducteurs. Ces synthèses ont également générées des matériaux avec des anions originaux. Deux méthodes de détermination de la charge sur les TMTSF ont été comparées sur plusieurs conducteurs organiques, issus de ce travail ou d’une base de données cristallographiques