Edge modification of PAHs: the effect of embedded heterocycles on the aromaticity pattern

International audienceAromaticity studies carried out on the condensed model system 2 with different heteroatoms showed that the NICS(1) aromaticity in the five-membered ring correlates with that in the parent five-membered ring having the same heteroelement. Although the local aromaticity pattern is clearly determined by the Clar structure, as evidenced by the local aromaticity values in the reference molecules R1-3, the modifying effect of the heteroatom is significant. The correlation between the NICS(1)5 and NICS(1)6 aromaticities of the neighbouring rings is excellent, by modification of the heterocycle, we can engineer the aromaticity of the connecting six-membered ring as well. Geometry based aromaticity indices do not correlate well with NICS values probably due to annellation effects between rings with different aromatic character. Calculations with the different tested basis sets don’t show significant differences, therefore the use of the computationally cheaper methods is envisaged during further investigations of corresponding systems with extended π-framework

Synthèse et caractérisation de nouveaux matériaux organophosphorés pour des applications en optoélectronique

Ce manuscrit décrit la synthèse et la caractérisation de nouvelles molécules incluant un cœur organophosphoré, le phosphole. Certaines de ces molécules ont été utilisées pour la fabrication de dispositifs OLEDs ou de cellules photovoltaïques organiques. Le premier chapitre fait un état de l'art de la chimie du phosphole dans le domaine des matériaux organiques entre 2010 et 2013. Le second chapitre décrit la synthèse et l'étude physico-chimique de molécules qui permettent de moduler l'angle de torsion dans les systèmes p conjugués pour faire varier les propriétés optiques et rédox. Une de ces molécules a permis la fabrication d'une diode blanche organique. Le troisième chapitre de ce manuscrit présente une structure tridimensionnelle intéressante, le 1,1-biphosphole. En plus de posséder une structure tridimensionnelle, ces structures présentent un mode de conjugaison original, la conjugaison -p, qui permet de réduire l'écart HO-BV de nos systèmes. Une de ces molécules a permis la fabrication de la première cellule photovoltaïque organique avec un dérivé du phosphole inséré dans la couche active. Dans une deuxième partie, ce chapitre traite également de la réactivité originale du 1,1'-biphosphole qui permet de fonctionnaliser l'atome de phosphore par une simple substitution nucléophile, permettant d'insérer une grande variété de substituants pour moduler les propriétés des molécules. Pour finir, ce manuscrit présente un quatrième chapitre qui implique le phosphole comme unité coordinante afin de réaliser des nouveaux complexes qui permettent de réaliser une ortho-métallation par activation C-H. De nouveaux complexes ortho-métallés d'Ir(III) et de Rh(III) ont été synthétisés et caractérisés.This thesis describes the synthesis and the characterization of new molecules including an organophosphorous unit, the phosphole ring. Some molecules have been used to build devices like organic light emitting diodes or organic photovoltaic cells.The first chapter describes the state of the art of the phosphole chemistry in organic materials between 2010 and 2013. The second chapter describes molecules having a tuneable twist angle allowing a fine control of the properties of the molecules like the HOMO-LUMO gap. One of those molecules has been used to build a white organic light emitting diode. The third chapter of this thesis presents an interesting three dimensional structure, the 1,1'-biphosphole. Beside this three dimensional structure, the molecules possess an original conjugation mode, the -p conjugation which allows a decrease of the HOMO-LUMO gap. One molecule from this chapter was used as absorber in organic photovoltaic cell. In the second part of this chapter, the 1,1'-biphosphole structure shows an interesting reactivity toward nucleophilic attack in order to functionalize the phosphorus center. This reactivity has been used to make new molecules and offer the opportunity to attach a wide range of substituents to the phosphorus atom in order to tune the properties of the molecules. The fourth chapter deals with the coordination chemistry of the phosphole in order to realize new ortho-metalated complexes. New Ir(III) and Rh(III) complexes have been synthesized and characterized.RENNES1-Bibl. électronique (352382106) / SudocSudocFranceF

Fluxional Behaviour of Phosphole and Phosphine Ligands on Triosmium Clusters

International audienceThe unsaturated cluster [Os3(μ-H)2(CO)10] reacts with a variety of π-conjugated phosphole ligands: 2,5-bis(2-thienyl)-1-phenylphosphole, 2,5-bis(2-pyridyl)-1-phenylphosphole, and 1,2,5-triphenylphosphole, to give the monosubstituted [Os3(μ-H)(H)(CO)10(P)] and [Os3(μ-H)2(CO)9(P)] derivatives. Variable-temperature 1H NMR studies for the decacarbonyltriosmium complexes show that the hydride ligands undergo fluxional behavior and its decarbonylation gave the nonacarbonyl unsaturated species with equivalent hydrides. An X-ray crystallographic analysis of [Os3(μ-H)2(CO)9(P)] (2b) (P = 1,2,5-triphenylphosphole) is reported. From 2,5-bis(2-pyridyl)-1-phenylphosphole four isomers are obtained, the 1H NMR spectrum at low temperature indicates that the phosphole ligand may occupy pseudoaxial and equatorial sites at one of the osmium atoms bearing the bridging hydride. The reaction of [Os3(CO)10(CH3CN)2] with cyanoethyldiphenylphosphine affords mono- and bis(phosphine)-substituted clusters. The X-ray crystal structure of the monosubstituted [Os3(CO)11(η1-PC15H14N)] (3) derivative is discussed. The dynamic behavior observed for [Os3(CO)10(η1-PC15H14N)2] (4) is studied by variable-temperature 1H and 31P{1H} NMR spectroscopy. The latter studies show a mixture of two geometric isomers, which are in dynamic equilibrium at room temperature where the 1,2-trans–trans isomer (4a) is favored, whose molecular structure has been determined by X-ray crystallography

Synthesis, electronic properties and OLED devices of chromophores based on λ5‐phosphinines

A new series of 2,4,6‐triaryl‐λ5‐phosphinines have been synthesized that contain different substituents both on the carbon backbone and the phosphorus atom of the six‐membered heterocycle. Their optical and redox properties were studied in detail, supported by in‐depth theoretical calculations. The modularity of the synthetic strategy allowed the establishment of structure–property relationships for this class of compounds and an OLED based on a blue phosphinine emitter could be developed for the first time

Rhenium complexes bearing phosphole-pyridine chelates: simple molecules with large chiroptical properties.

International audienceThe synthesis and chiroptical properties of chiral rhenium complexes bearing mono- or di-topic phosphole ligands are described. [on SciFinder(R)

Synthesis, Electronic Properties and WOLED Devices of Planar Phosphorus-Containing Polycyclic Aromatic Hydrocarbons

International audienceWe describe the synthesis and the physical properties of polyaromatic hydrocarbons (PAHs) containing a phosphorus atom at the edge. In particular, the impact of the successive addition of aromatic rings on the electronic properties was investigated by experimental (UV/Vis absorption, fluorescence, cyclic voltammetry) and theoretical studies (DFT). The physical properties recorded in solution and in the solid state showed that the P-containing PAHs exhibit properties expected for an emitter in white organic light-emitting diodes (WOLEDs)

Conjugated oligomers with alternating heterocycles from a single monomer:synthesis and demonstration of electroluminescence

International audienceConjugated oligomers based on two different heterocycles are typically prepared by step growth polycondensation cross-coupling methods from two monomers X-Cycle1-X and M-Cycle2-M with no control of the regioselectivity. In this work, we used a new synthetic strategy that involves an extremely chemoselective reaction of a dielectrophilic compound, X1 Cycle1 X2, with a dinucleophilic component, M1-Cycle2-M2, under Stille conditions. The resulting monomers, X1 Cycle1 Cycle2-M2 are di-heterocyclic push pull monomers that still contain a nucleophilic site (boronic acid) and electrophilic site (bromide) and are set up for a controlled polymerization under Suzuki conditions. In this way, two semiconducting oligomers, based on thiophene / benzene and thiophene / pyridine motifs were synthesized. Both oligomers were characterized in terms of their, thermal, electrochemical, absorption, emission and electroluminescence properties

Topologically diverse polycyclic aromatic hydrocarbons from pericyclic reactions with polyaromatic phospholes

International audiencePolycyclic Aromatic Hydrocarbons (PAHs) with planar, twisted and negatively curved topologies were obtained from polycyclic phospholes using pericyclic reactions. Deviation from planarity is due to steric interaction between the PAH core and the ester substituents. These structural effects on the optical and redox properties were studied and rationalized through DFT calculations. This synthetic approach thus allows the preparation of topologically diverse PAHs allowing finetuning their electronic properties, with potential applications in organic electronics

Stereospecific synthesis of chiral P-containing polyaromatics based on 7-membered P-rings

International audienceWe present the stereospecific synthesis of helicenoid-based phosphepines (7-membered P-rings) as well as chiral P-containing polycyclic aromatic hydrocarbons. In these systems, an axial to central chirality transfer takes place from the BINAP moiety to the P-atom. The impact of the molecular design on the structure, the (chir)optical (including circularly polarized luminescence) and redox properties are investigated

Benzofuran-fused Phosphole: Synthesis, Electronic, and Electroluminescence Properties

International audienceA synthetic route to novel benzofuran-fused phosphole derivatives 3-5 is described. These compounds showed optical and electrochemical properties that differ from their benzothiophene analog. Preliminary results show that 4 can be used as an emitter in OLEDs, illustrating the potential of these new compounds for opto-electronic applications