RESUMEN
Perylenediimides (PDIs) are composed of a central perylene ring, on which are grafted two imide groups at the peri positions. Thionated PDIs are characterized by the substitution of one or more oxygen atoms of these imide functions with sulfur atoms. This structural modification alters the electronic properties with a redshift of the optical absorption accompanied by modification of the charge transport characteristics compared to their non-thionated counterparts. These properties make them suitable candidates for applications in optoelectronic devices, such as organic light-emitting diodes and organic photovoltaics. Moreover, the presence of sulfur atom(s) can favor the promotion of reactive oxygen species production for photodynamic and photothermal therapies. These thionated PDIs can be synthesized through the post-functionalization of PDIs by using a sulfurizing reagent. Nevertheless, the main drawbacks remain the difficulties in adjusting the degree of thionation and obtaining tri- and tetrathionated PDIs. Up to now, this thionation reaction has been described almost exclusively using Lawesson's reagent. In the current study, we present our first investigations into an alternative reagent to enhance selectivity and achieve a greater degree of thionation. The association of phosphorus pentasulfide with hexamethyldisiloxane (Curphey's reagent) clearly demonstrated higher reactivity compared with Lawesson's reagent to attain multi-thionated PDIs.
RESUMEN
The use of perylenediimide (PDI) building blocks in materials for organic electronic is of considerable interest. This popular n-type organic semiconductor is tuned by introducing peripheral groups in their ortho and bay positions. Such modifications radically alter their optoelectronic properties. In this article, we describe an efficient method to afford regioisomerically pure 1,6/7-(NO2 )2 - and (NH2 )2 -PDIs employing two key steps: the selective crystallization of 1,6-(NO2 )2 -perylene-3,4,9,10-tetracarboxy tetrabutylester and the nitration of regiopure 1,7-Br2 -PDI with silver nitrite. The optoelectronic properties of the resulting regioisomerically pure dinitro, diamino-PDIs and bisazacoronenediimides (BACDs) are reported and demonstrate the need to separate both regioisomers of such n-type organic semiconductors for their inclusion in advanced optoelectronic devices. For the first time, the two regioisomers of the same PDI starting material are available on the multigram scale, which will stimulate the exploration of regioisomerism/properties relationship for this family of dyes.
Asunto(s)
Perileno , Estructura Molecular , Perileno/química , Dióxido de Nitrógeno , Imidas/químicaRESUMEN
The emblematic perylenediimide (PDI) motif which was initially used as a simple dye has undergone incredible development in recent decades. The increasing power of synthetic organic chemistry has allowed it to decorate PDIs to achieve highly functional dyes. As these PDI derivatives combine thermal, chemical and photostability, with an additional high absorption coefficient and near-unity fluorescence quantum yield, they have been widely studied for applications in materials science, particularly in photovoltaics. Although PDIs have always been in the spotlight, their asymmetric counterparts, perylenemonoimide (PMI) analogues, are now experiencing a resurgence of interest with new efforts to create architectures with equally exciting properties. Namely, their exceptional fluorescence properties have recently been used to develop novel systems for applications in bioimaging, biosensing and photodynamic therapy. This review covers the state of the art in the synthesis, photophysical characterizations and recently reported applications demonstrating the versatility of these two sister PDI and PMI compounds. The objective is to show that after well-known applications in materials science, the emerging trends in the use of PDI- and PMI-based derivatives concern very specific biomedicinal applications including drug delivery, diagnostics and theranostics.
Asunto(s)
Colorantes Fluorescentes , Fotoquimioterapia , Colorantes Fluorescentes/química , Imidas/químicaRESUMEN
We report herein an unprecedented palladium-catalyzed cross-coupling reaction between mononitro-perylenediimide (PDI) and various arylstannanes. Optimized conditions developed with this Stille-type reaction allow the grafting of (hetero)aryls of various electronic nature in the bay region of PDIs. Moreover, we capitalized on the high selectivity of this cross-coupling through the desymmetrization of the dinitro-PDI substrate.
RESUMEN
An overview of the different covalent bonding synthetic strategies of two electron acceptors leading to fullerene-perylenediimide (C60-PDI)-based systems, essentially dyads and triads, is presented, as well as their more important applications. To go further in the development of such electron and photoactive assemblies, an original aromatic platform 5-benzyloxy-3-formylbenzoic acid was synthesized to graft both the PDI dye and the fullerene C60. This new C60-PDI dyad exhibits a free anchoring phenolic function that could be used to attach a third electro- and photoactive unit to study cascade electron and/or energy transfer processes or to obtain unprecedented side-chain polymers in which the C60-PDI dyads are attached as pendant moieties onto the main polymer chain. This C60-PDI dyad was fully characterized, and cyclic voltammetry showed the concomitant reduction process onto both C60 and PDI moieties at identical potential. A quasi-quantitative quenching of fluorescence was demonstrated in this C60-PDI dyad, and an intramolecular energy transfer was suggested between these two units. After deprotection of the benzyloxy group, the free hydroxyl functional group of the platform was used as an anchor to reach a new side-chain methyl methacrylate-based polymer in which the PDI-C60 dyad units are located as pendants of the main polymer chain. Such polymer which associates two complementary acceptors could find interesting applications in optoelectronics and in particular in organic solar cells.
Asunto(s)
Fulerenos , Imidas , Metacrilatos , Perileno/análogos & derivados , PolímerosRESUMEN
Bay decoration of perylenediimide (PDI) is an attractive approach for tuning the optoelectronic properties of the dye as well as breaking backbone planarity, which provides the possibility of preventing the undesired formation of aggregates. This is usually performed through successive bis-bromination of PDI and pallado-catalyzed cross-coupling, which leads to symmetric triads. We now describe an efficient synthetic strategy for desymmetrization of the accepting PDI core by starting from its bis-nitration. To this end, Suzuki-Miyaura Couplings (SMC) were carried out on a mixture of 1,6- and 1,7-dinitroPDI regioisomers to add triphenylamine donating moieties and obtain donor-acceptor-donor triads. Investigation of the reactivity of dinitro PDI derivatives toward SMC has allowed us to access unprecedented asymmetric π-conjugated PDI-centered triads. These 1,6- and 1,7-PDI based triads, prepared as regioisomeric mixtures, were successfully separated and their spectroscopic, crystallographic and optoelectronic differences are reported.
RESUMEN
AzaBenzannulated perylenediimide (AzaBPDI) dyes were synthesized in high yields via a new reaction sequence involving an imine condensation followed by visible light-induced photocyclization. The large scope and efficiency of this alternative to the Pictet-Spengler reaction are demonstrated, allowing easy preparation of dimeric AzaBPDI as potential non-fullerene acceptors for organic solar cells.
RESUMEN
Intramolecular imine photocyclization has been explored for grafting on the bay region of perylenediimide (PDI) different electro- and photoactive chromophores to achieve new AzaBenzannulated-PDI (AzaBPDI) dyads. Triphenylamine (TPA), fluorene (Fl), perylenemonoimide (PMI), and perylenediimide (PDI) units have been successfully assembled to AzaBPDI using this straightforward one-pot synthesis starting from the easily accessible 1-aminoPDI. This original procedure was compared to the well-known Pictet-Spengler reaction and appears to be an attractive alternative in terms of versatility and efficiency with higher yields obtained. The optical and electrochemical properties of these molecular systems demonstrated large absorption capabilities in the visible range, good accepting abilities with low LUMO levels, and efficient electronic interactions between chromophoric units such as energy or electron transfers. In addition, with their large dihedral angle estimated by theoretical calculations, those dyads should present interesting applications in various organic optoelectronic devices. In particular, the PMI-AzaBPDI and PDI-AzaBPDI dyads presenting low LUMO levels, a broad absorption in the visible range, and a twisted conformation make them good candidates as non-fullerene acceptors in organic solar cells.
RESUMEN
Perylenediimide (PDI) is one of the most important classes of dyes and is intensively explored in the field of functional organic materials. The functionalization of this electron-deficient aromatic core is well-known to tune the outstanding optoelectronic properties of PDI derivatives. In this respect, the functionalization has been mostly addressed in bay-positions to halogenated derivatives through nucleophilic substitutions or metal-catalyzed coupling reactions. Being aware of the synthetic difficulties of obtaining the key intermediate 1-bromoPDI, we will present as an alternative in this review the potential of 1-nitroPDI: a powerful building block to access a large variety of PDI-based materials.
Asunto(s)
Imidas/química , Nitrocompuestos/síntesis química , Perileno/análogos & derivados , Catálisis , Estructura Molecular , Nitrocompuestos/química , Perileno/químicaRESUMEN
New penta(organo)fullerenes donor-acceptor systems bearing five tetrathiafulvalene recognition units have been synthesized to promote self-assemblies similar in appearance to shuttlecocks nested into each other thanks to the conical host cavity created around the fullerene together with the π-π and electronic interactions.
RESUMEN
Glycoluril-based molecular clips incorporating tetrathiafulvalene (TTF) sidewalls have been synthesized through different strategies with the aim of investigating the effect of electrochemical and spatial properties for binding neutral accepting guests. We have in particular focused our study on the spacer extension in order to tune the intramolecular TTF···TTF distance within the clip and, consequently, the redox behavior of the receptor. Carried out at different concentrations in solution, electrochemical and spectroelectrochemical experiments provide evidence of mixed-valence and/or π-dimer intermolecular interactions between TTF units from two closed clips. The stepwise oxidation of each molecular clip involves an electrochemical mechanism with three one-electron processes and two charge-coupled chemical reactions, a scheme which is supported by electrochemical simulations. The fine-tunable π-donating ability of the TTF units and the cavity size allow to control binding interaction towards a strong electron acceptor such as tetrafluorotetracyanoquinodimethane (F4-TCNQ) or a weaker electron acceptor such as 1,3-dinitrobenzene (m-DNB).
RESUMEN
Camalexin, the characteristic phytoalexin of Arabidopsis thaliana, inhibits growth of the fungal necrotroph Alternaria brassicicola. This plant metabolite probably exerts its antifungal toxicity by causing cell membrane damage. Here we observed that activation of a cellular response to this damage requires cell wall integrity (CWI) and the high osmolarity glycerol (HOG) pathways. Camalexin was found to activate both AbHog1 and AbSlt2 MAP kinases, and activation of the latter was abrogated in a AbHog1 deficient strain. Mutant strains lacking functional MAP kinases showed hypersensitivity to camalexin and brassinin, a structurally related phytoalexin produced by several cultivated Brassica species. Enhanced susceptibility to the membrane permeabilization activity of camalexin was observed for MAP kinase deficient mutants. These results suggest that the two signalling pathways have a pivotal role in regulating a cellular compensatory response to preserve cell integrity during exposure to camalexin. AbHog1 and AbSlt2 deficient mutants had reduced virulence on host plants that may, at least for the latter mutants, partially result from their inability to cope with defence metabolites such as indolic phytoalexins. This constitutes the first evidence that a phytoalexin activates fungal MAP kinases and that outputs of activated cascades contribute to protecting the fungus against antimicrobial plant metabolites.
Asunto(s)
Alternaria/efectos de los fármacos , Alternaria/fisiología , Antifúngicos/toxicidad , Pared Celular/fisiología , Glicerol/metabolismo , Sesquiterpenos/toxicidad , Estrés Fisiológico , Adaptación Fisiológica , Alternaria/crecimiento & desarrollo , Arabidopsis/química , Brassica/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Eliminación de Gen , Perfilación de la Expresión Génica , Regulación Fúngica de la Expresión Génica/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Modelos Biológicos , Concentración Osmolar , Filogenia , Homología de Secuencia de Aminoácido , Virulencia , FitoalexinasRESUMEN
An efficient synthesis of unprecedented fused extended-tetrathiafulvalene-dipyridoquinoxaline (exTTF-dpq) dyad is described through the Horner-Wardsworth-Emmons olefination methodology from the dipyrido[3,2-a:2',3'-c]-benzo[3,4]phenazine-11,16-quinone (NqPhen) ligand starting material. This exTTF-dpq dyad is demonstrated to act as a dual redox and colorimetric sensor for cations exploiting the proximity between the redox tetrathiafulvalene and the optical phenanthroline detecting sites. Its ability for sensing cations from the d-group metal transitions (Fe(2+), Ni(2+), and Zn(2+)) and also with varied cations such as Ca(2+) and Pb(2+) is presented.
Asunto(s)
Colorantes Fluorescentes/química , Compuestos Heterocíclicos/química , Fenantrolinas/química , Cationes/química , Cristalografía por Rayos X , Modelos Moleculares , Estructura MolecularRESUMEN
Intense current interest in supramolecular chemistry is devoted to the construction of molecular assemblies displaying controlled molecular motion associated to recognition. On this ground, molecular clips and tweezers have focused an increasing attention. This tutorial review points out the recent advances in the construction of always more sophisticated molecular clips and tweezers, illustrating their remarkably broad structural variety and focusing on their binding ability towards neutral guests. A particular attention is brought to recent findings in dynamic molecular tweezers whose recognition ability can be regulated by external stimuli. Porphyrin-based systems will not be covered here as this very active field has been recently reviewed.
Asunto(s)
Modelos Químicos , Acridinas/química , Alquinos/química , Antracenos/química , Benzofuranos/química , Fulerenos/química , Imidazoles/química , Conformación Molecular , Porfirinas/química , Rotaxanos/químicaRESUMEN
This study aims to present the fabrication of colloidal photonic crystals (PC) with increased fluorescence properties. The use of a highly fluorescent perylenediimide derivate (PDI) during the soap-free emulsion polymerization of styrene-acrylic acid resulted in monodisperse core-shell particles which allowed the fabrication of PC films. The properties of the hybrid material were studied in comparison with hybrid materials obtained by impregnation of films with chromophore solutions. In both cases an increase of the fluorescence response was observed in addition to a blue shift for the PDI core particles, proving the incorporation of the dye inside the copolymer particles.
RESUMEN
A methodology is proposed to provide direct access in good yields to peptide residues-appended perylenediimides PDI-(Cl(4))-[Gly-Ala(OEt)](2), 2a, PDI-(Cl(4))-[Gly-Val(OEt)](2), 2b and PDI-(Cl(4))-[Gly-Gly(OEt)](2), 2c from a generic perylenediimide (PDI) platform symmetrically functionalized with carboxylic acids at the imide sites, PDI-(Cl(4))-[Gly(OH)](2), 1. The latter is obtained in good purity by a non classical two-steps route avoiding the many, notoriously cumbersome successive chromatography steps typical of PDI chemistry, and including a single final purification allowing to crystallize the water soluble pure diacid 1, of great interest in its own right for further developments in a variety of fields. Then, the synthesis, crystallization and analysis of the crystal structures of 2a and 2b reveal a common pattern of self-assembly of the outer peptide residues based on collections of parallel N-H···O peptidic hydrogen bonds running alongside stacks where the constraints imposed upon on the inner PDI skeletons by long range interaction of these parallel electric dipoles reduce the dihedral angles around the bay regions by as much as 11% down to 32°.
Asunto(s)
Aminoácidos/química , Imidas/química , Péptidos/química , Perileno/análogos & derivados , Cristalografía por Rayos X , Hidrógeno/química , Modelos Moleculares , Estructura Molecular , Nitrógeno/química , Oxígeno/química , Perileno/químicaRESUMEN
A benzo[ghi]perylenetriimide (BPTI) derivative bearing a terminal azido group on the expanded π-conjugated backbone has been synthesized and characterized. This promising photo- and electroactive BPTI motif has been used to obtain an original penta(organo)fullerene as a promising multi-electron acceptor system. Our studies show its self-assembly resulting from aggregation via π-π stacking interaction in solution and in the solid state.
RESUMEN
A glycoluril-based molecular clip incorporating two tetrathiafulvalene (TTF) sidewalls has been synthesized using a straightforward Diels-Alder synthetic route and its ability to self-assemble with fullerene C60 in a 2 : 1 stoichiometry has been demonstrated in solution.
RESUMEN
Alternaria brassicicola causes black spot disease in Brassicaceae. During host infection, this necrotrophic fungus is exposed to various antimicrobial compounds, such as the phytoalexin brassinin which is produced by many cultivated Brassica species. To investigate the cellular mechanisms by which this compound causes toxicity and the corresponding fungal adaptive strategies, we first analyzed fungal transcriptional responses to short-term exposure to brassinin and then used additional functional approaches. This study supports the hypothesis that indolic phytoalexin primarily targets mitochondrial functions in fungal cells. Indeed, we notably observed that phytoalexin treatment of A. brassicicola disrupted the mitochondrial membrane potential and resulted in a significant and rapid decrease in the oxygen consumption rates. Secondary effects, such as Reactive oxygen species production, changes in lipid and endoplasmic reticulum homeostasis were then found to be induced. Consequently, the fungus has to adapt its metabolism to protect itself against the toxic effects of these molecules, especially via the activation of high osmolarity glycerol and cell wall integrity signaling pathways and by induction of the unfolded protein response.
RESUMEN
Fullerene C 60-perylene-3,4-mono(dicarboximide) (C 60-PMI) dyads 1- 3 were synthesized in the search for new light-harvesting systems. The synthetic strategy to the PMI intermediate used a cross-coupling Suzuki reaction for the introduction of a formyl group in the ortho, meta, or para position. Subsequent 1,3-dipolar cycloaddition with C 60 led to the target C 60-PMI dyad. Cyclic voltammetry showed that the first one-electron reduction process unambiguously occurs onto the C 60 moiety and the following two-electron process corresponds to the concomitant second reduction of C 60 and the first reduction of PMI. A quasi-quantitative quenching of fluorescence was shown in dyads 1- 3, and an intramolecular energy transfer was suggested to occur from the PMI to the fullerene moiety. These C 60-PMI dyads constitute good candidates for future photovoltaic applications with expected well-defined roles for both partners, i.e., PMI acting as a light-harvesting antenna and C 60 playing the role of the acceptor in the photoactive layer.