37 research outputs found
Modulation des propriétés d'isomères de diSpirofluorène-indénofluorène pour des applications en diodes électroluminescentes organiques bleues
This work is focused on the synthesis and study of 3π-2spiro molecules, DiSpiroFluorene-IndenoFluorene (DSF-IF), having different structures. These compounds are aimed to be used as blue light emitting layer in OLED. The first chapter describes the working principles of OLEDs and their different structures. It focuses then on different approaches of molecular engineering towards ambipolar molecules that can be used in single layer devices. The second chapter is devoted to the study of two different families of DSF-IF isomers that are obtained through one and the same synthetic intermediate. The different structure of the indenofluorene backbone, (1,2-b) or (2,1-a), leads to different properties, mainly because of intramolecular π-π interactions. The third chapter is related to the development of functionalized DSF-IF with electron donor and/or acceptor groups. The impact of the electron donor or acceptor groups substituted on the DSF-IF are discussed, especially the intramolecular charge transfer phenomena. In the last part, some of these new molecules have been tested as emitting layers in OLEDsCe travail porte sur la synthèse et l'étude de molécules d'architecture 3π-2spiro, DiSpiroFluorène-IndénoFluorène (DSF-IF), de structures différentes. La finalité de ces composés est leur utilisation en tant que couche émissive de lumière bleue dans des diodes électroluminescentes organiques (OLED). Le premier chapitre bibliographique décrit tout d'abord le principe de fonctionnement des OLEDs et leurs différentes structures. Il se poursuit par la description de différentes approches d'ingénierie moléculaires visant à obtenir des molécules ambipolaires capables d'être utilisées dans des dispositifs monocouches. Le second chapitre concerne l'étude de deux familles d'isomères de DSF-IF obtenus au travers d'un seul et même intermédiaire de synthèse. La structure différente du corps indénofluorène, (1,2-b) ou (2,1-a), entraîne des propriétés différentes, en particuliers liées à des interactions π-π intramoléculaires dans les isomères de géométrie (2,1-a). Le troisième chapitre est consacré à la mise au point de DSF-IF fonctionnalisés par des groupements donneur et/ou accepteurs d'électrons. L'impact de l'ajout de groupements transporteurs de charges sur le corps DSF-IF est discuté et en particulier les phénomènes de transfert de charge intramoléculaires. Enfin, le dernier chapitre traite de l'étude de certaines molécules synthétisées précédemment en tant que couches émissives dans des OLEDs
Intramolecular excimer emission as a blue light source in fluorescent organic light emitting diodes: a promising molecular design
International audienceIntramolecular excimer emission arising from organic molecules as a blue light source in fluorescent Small Molecule Organic Light Emitting Diodes (SMOLEDs) is almost absent from the literature. In this work, three aryl-substituted DiSpiroFluorene-IndenoFluorenes (DSF-IFs 1-3) possessing different fluorescent properties due to their different main emitters have been investigated through a structure-property relationship study. Due to its particular geometry, the rigid DSF-IF platform 2 allows an 'aryl/fluorene/aryl' dimer to be preformed in the ground state leading, in the excited state, to a deep blue fluorescent emission through strong π-π intramolecular interactions between the two 'aryl/fluorene/aryl' arms. 2 has been successfully used as an emitting layer in a SMOLED with electroluminescence arising from electrogenerated intramolecular excimers and the properties of these excimer-based OLEDs have been compared to those of two model compounds (1 and 3). The simple and non-optimized double-layer device displays a deep blue colour (CIE coordinates: 0.19; 0.18) exhibiting a luminance of 510 Cd m−2 with a luminous efficiency of ca. 0.1 Cd A−1. This work is, to the best of our knowledge, the first rational and comparative study describing an intramolecular excimer based-SMOLED
A robust pure hydrocarbon derivative based on the (2,1-b)-indenofluorenyl core with high triplet energy level.
International audienceA unique (2,1-b)-indenofluorenyl core flanked with two spirofluorene units, possessing a high triplet energy value and excellent thermal/morphological stability, is reported
Investigation of Ester- and Amide-Linker-Based Porous Organic Polymers for Carbon Dioxide Capture and Separation at Wide Temperatures and Pressures
Organic compounds, such as covalent organic framework, metal–organic frameworks, and covalent organic polymers have been under investigation to replace the well-known amine-based solvent sorption technology of CO2 and introduce the most efficient and economical material for CO2 capture and storage. Various organic polymers having different function groups have been under investigation both for low and high pressure CO2 capture. However, search for a promising material to overcome the issues of lower selectivity, less capturing capacity, lower mass transfer coefficient and instability in materials performance at high pressure and various temperatures is still ongoing process. Herein, we report synthesis of six covalent organic polymers (COPs) and their CO2, N2, and CH4 adsorption performances at low and high pressures up to 200 bar. All the presented COPs materials were characterized by using elemental analysis method, Fourier transform infrared spectroscopy (FTIR) and solid state nuclear magnetic resonance (NMR) spectroscopy techniques. Physical properties of the materials such as surface areas, pore volume and pore size were determined through BET analysis at 77 K. All the materials were tested for CO2, CH4, and N2 adsorption using state of the art equipment, magnetic suspension balance (MSB). Results indicated that, amide based material i.e. COP-33 has the largest pore volume of 0.2 cm2/g which can capture up to the maximum of 1.44 mmol/g CO2 at room temperature and at pressure of 10 bar. However, at higher pressure of 200 bar and 308 K ester-based compound, that is, COP-35 adsorb as large as 144 mmol/g, which is the largest gas capturing capacity of any COPs material obtained so far. Importantly, single gas measurement based selectivity of COP-33 was comparatively better than all other COPs materials at all condition. Nevertheless, overall performance of COP-35 rate of adsorption and heat of adsorption has indicated that this material can be considered for further exploration as efficient and cheaply available solid sorbent material for CO2 capture and separation.Qatar National Research Fund, National Priorities Research Program grant (NPRP 5-499-1-088)
Modulation des propriétés d'isomères de diSpirofluorène-indénofluorène pour des applications en diodes électroluminescentes organiques bleues
Ce travail porte sur la synthèse et l'étude de molécules d'architecture 3p-2spiro, DiSpiroFluorène-IndénoFluorène (DSF-IF), de structures différentes. La finalité de ces composés est leur utilisation en tant que couche émissive de lumière bleue dans des diodes électroluminescentes organiques (OLED). Le premier chapitre bibliographique décrit tout d'abord le principe de fonctionnement des OLEDs et leurs différentes structures. Il se poursuit par la description de différentes approches d'ingénierie moléculaires visant à obtenir des molécules ambipolaires capables d'être utilisées dans des dispositifs monocouches. Le second chapitre concerne l'étude de deux familles d'isomères de DSF-IF obtenus au travers d'un seul et même intermédiaire de synthèse. La structure différente du corps indénofluorène, (1,2-b) ou (2,1-a), entraîne des propriétés différentes, en particuliers liées à des interactions p-p intramoléculaires dans les isomères de géométrie (2,1-a). Le troisième chapitre est consacré à la mise au point de DSF-IF fonctionnalisés par des groupements donneur et/ou accepteurs d'électrons. L'impact de l'ajout de groupements transporteurs de charges sur le corps DSF-IF est discuté et en particulier les phénomènes de transfert de charge intramoléculaires. Enfin, le dernier chapitre traite de l'étude de certaines molécules synthétisées précédemment en tant que couches émissives dans des OLEDs.This work is focused on the synthesis and study of 3p-2spiro molecules, DiSpiroFluorene-IndenoFluorene (DSF-IF), having different structures. These compounds are aimed to be used as blue light emitting layer in OLED. The first chapter describes the working principles of OLEDs and their different structures. It focuses then on different approaches of molecular engineering towards ambipolar molecules that can be used in single layer devices. The second chapter is devoted to the study of two different families of DSF-IF isomers that are obtained through one and the same synthetic intermediate. The different structure of the indenofluorene backbone, (1,2-b) or (2,1-a), leads to different properties, mainly because of intramolecular p-p interactions. The third chapter is related to the development of functionalized DSF-IF with electron donor and/or acceptor groups. The impact of the electron donor or acceptor groups substituted on the DSF-IF are discussed, especially the intramolecular charge transfer phenomena. In the last part, some of these new molecules have been tested as emitting layers in OLEDs.RENNES1-BU Sciences Philo (352382102) / SudocSudocFranceF
Modulation of the electronic properties of 3π-2spiro compounds derived from bridged oligophenylenes : a structure-property relationship.
International audience3π-2spiro compounds are constituted of three π-systems linked through two shared spiro carbons leading to a three-dimensional architecture. The modulation of the electronic properties of such molecular systems can be achieved through the modification and/or substitution of their different π-systems and by the modification of their geometry. The present work is focused on the tuning of the electrochemical properties of a wide range of 3π-2spiro compounds based on fluorenyl, xanthenyl, 2,7-disubstituted fluorenyl, 1,2-b- or 2,1-a-indenofluorenyl, and pentaphenylenyl fragments with a main emphasis on the localization of the successive electron transfers. A detailed structure-property relationship study of interest for the organic electronics scientific community is then drawn