Triphenylmethylium-Based Multitopic Two-Photon Absorbers: Synthesis and Characterization

During this PhD, new organic and organometallic triphenylmethylium dyes were synthesized. Due to their multipolar structure, these compounds have been anticipated to possess strong nonlinear optical (NLO) properties which could be of interest in many fields. These characteristics, and more precisely their two-photon absorption (TPA) properties, make them attractive for the design of high technology materials (microfabrication, imaging, optical devices, etc). However, their multiphoton absorption properties and other related nonlinear optical (NLO) effects have not been thoroughly investigated to date, in spite of their promising potential. In this respect, a family of organic derivatives has been synthesized to confirm their potential as two-photon absorbers, which was established thanks to Z-scan measurements. Organometallic compounds bearing electron-releasing groups such as «Fe(η5-C5Me5)(κ2-dppe)C≡C−» , « Ru(Cl)(κ2-dppe) 2C≡C− » or ethynylferrocene were then synthesized and fully characterized. These organometallic dyes should possess larger TPA cross-sections (and also larger third-order NLO properties) in the NIR range than their organic counterparts. Furthermore, these redox-active metal centers permit access to electro-switchable molecules. In this respect, along with the data already gathered on these derivatives, the study of their cubic NLO properties in their different redox states will now contribute to a better understanding of the underlying electronic phenomena and the role played by the organic and organometallic moieties in such architectures. Keywords: NonLinear Optics, Biphotonic absorption, Malachite Green, Violet Crystal, Organoiron, Organoruthenium, ferrocene, redox commutatio

Constantes et variations autour d’un modèle

Depuis les années 2000 avec l’essor de l’archéologie préventive, on constate, en Bretagne, un renouvellement important des données céramiques notamment avec la mise au jour de contextes domestiques du Bronze ancien. Ces découvertes permettent, aujourd’hui, de disposer de contextes clos et bien datés, propices à la mise en place d’une approche technologique. Cette approche permet d’intégrer les nouveaux corpus domestiques à la réflexion générale d’un point de vue typochronologique, mais également au plan des dynamiques culturelles et des réseaux d’échanges entretenus à l’échelle de la façade atlantique, tout particulièrement au travers des phénomènes d’emprunts, de copies et d’imitations.Since the 2000s with the rise of rescue archaeology, there is, in Brittany, a significant renewal of ceramic data especially with the discovery of domestic contexts of the early Bronze Age. These discoveries make it possible today to have enclosed and well-dated settings, conducive to the implementation of a technological approach. This approach makes it possible to integrate new domestic data to the overall reflection from a typochronological point of view, but also with regard to cultural dynamics and interaction networks maintained at the scale of the Atlantic seafront, especially through borrowing, copying and imitation phenomena.Desde los años 2000, y gracias al auge de la arqueología preventiva, se ha venido constatando una renovación importante de los datos cerámicos en el departamento de Bretaña, especialmente tras el descubrimiento de contextos domésticos del período del Bronce antiguo. Los hallazgos permiten disponer actualmente de contextos cerrados y bien fechados, propicios para la implementación de un enfoque tecnológico. Gracias a lo anterior se han podido integrar nuevos corpus domésticos a la reflexión general, tanto desde un punto de vista tipocronológico, como en el plano de las dinámicas culturales y de las redes de intercambio establecidas a escala de la fachada atlántica, en particular a través de fenómenos de adopción, copia e imitación

A Zinc(II) Tetraphenylporphyrin Peripherally Functionalized with Redox-Active "trans-[(η5-C5H5)Fe(η5-C5H4)C≡C](κ2- dppe)2Ru(C≡C)-" Substituents: Linear Electrochromism and Third-Order Nonlinear Optics

Dedicated to Dr. Claude Lapinte on the occasion of his retirement, in memory of the good times spent together in France and Australia.International audienceA nonametallic organometallic-coordination complex (4), assembled from redox-active ferrocenyl (Fc) and Ru(κ2-dppe)2 fragments (dppe = 1,2-bis(diphenylphosphino)ethane) as peripheral donor groups and a central Zn(II) tetraphenylporphyrin (ZnTPP) core, has been prepared and characterized. Complex 4 is obtained in one step from a pentametallic organometallic porphyrin precursor following substitution of the peripheral chloride ligands by ferrocenylalkynyl moieties (Ctriple bond; length of mdashCFc). The spectroelectrochemistry of 4, and that of previously reported porphyrins featuring related peripheral electron-rich d6-transition metal alkynyl units, has been investigated; the optical and redox properties of 4 are briefly discussed, and its potential, and that of a related pentanuclear tetraferrocenyl ZnTPP complex, to function as redox-switchable chromophores is examined. Preliminary studies of the cubic NLO properties of 4 have been undertaken by Z-scan studies at 560 nm and 630 nm, the results from which are also reported

Prognostic impact of vitamin B6 metabolism in lung cancer

Patients with non-small cell lung cancer (NSCLC) are routinely treated with cytotoxic agents such as cisplatin. Through a genome-wide siRNA-based screen, we identified vitamin B6 metabolism as a central regulator of cisplatin responses in vitro and in vivo. By aggravating a bioenergetic catastrophe that involves the depletion of intracellular glutathione, vitamin B6 exacerbates cisplatin-mediated DNA damage, thus sensitizing a large panel of cancer cell lines to apoptosis. Moreover, vitamin B6 sensitizes cancer cells to apoptosis induction by distinct types of physical and chemical stress, including multiple chemotherapeutics. This effect requires pyridoxal kinase (PDXK), the enzyme that generates the bioactive form of vitamin B6. In line with a general role of vitamin B6 in stress responses, low PDXK expression levels were found to be associated with poor disease outcome in two independent cohorts of patients with NSCLC. These results indicate that PDXK expression levels constitute a biomarker for risk stratification among patients with NSCLC.publishedVersio

Model inter-comparison on crop rotation effects ? an intermediate report

Data of diverse crop rotations from five locations across Europe were distributed to modelers to investigate the capability of models to handle complex crop rotations and management interactions

Absorbeurs Bi-photoniques multitopiques dérivés du triphenylmethane cation : synthèse et caractérisation

During this PhD, new organic and organometallic triphenylmethylium dyes were synthesized. Due to their multipolar structure, these compounds have been anticipated to possess strong nonlinear optical (NLO) properties which could be of interest in many fields. These characteristics, and more precisely their two-photon absorption (TPA) properties, make them attractive for the design of high technology materials (microfabrication, imaging, optical devices, etc…). However, their multiphoton absorption properties and other related nonlinear optical (NLO) effects have not been thoroughly investigated to date, in spite of their promising potential. In this respect, a family of organic derivatives has been synthesized to confirm their potential as two-photon absorbers, which was established thanks to Z-scan measurements. Organometallic compounds bearing electron-releasing groups such as «Fe(η5-C5Me5)(κ2-dppe)C≡C−» , « Ru(Cl)(κ2-dppe)2C≡C− » or ethynylferrocene were then synthesized and fully characterized. These organometallic dyes should possess larger TPA cross-sections (and also larger third-order NLO properties) in the NIR range than their organic counterparts. Furthermore, these redox-active metal centers permit access to electro-switchable molecules. In this respect, along with the data already gathered on these derivatives, the study of their cubic NLO properties in their different redox states will now contribute to a better understanding of the underlying electronic phenomena and the role played by the organic and organometallic moieties in such architectures.Au cours de cette thèse, de nouveaux dérivés organométalliques basés sur une structure triphénylméthylium ont été synthétisés. Ces composés, notamment grâce à leur structure multiplolaire, sont pressentis pour avoir des propriétés remarquables en optiques non linéaire (ONL) qui pourraient donner lieu à des développements appliqués dans plusieurs domaines. Ces caractéristiques, et plus précisément leur absorption biphotonique (A2P), en font des composés particulièrement intéressants pour l'industrie de pointe (microfabrication, imagerie, dispositifs optiques, etc.). Cependant, ces propriétés d'ONL et d'absorption biphotoniques n'ont été jusqu’à lors que peu étudiées, malgré leur potentiel prometteur. Dans un premier temps, une famille de nouveaux composés organiques présentant cette structure particulière, a donc été synthétisée afin de confirmer le potentiel d'absorption à deux photons de ces chromophores, notamment par des mesures Z-scan. Dans un second temps, la synthèse de d’analogues organométalliques ayant des groupes donneurs tels que «Fe(η5-C5Me5)(κ2-dppe)C≡C− , « Ru(Cl)(κ2-dppe)2C≡C− » ou ethynylferrocene a été réalisée et ces dérivés ont été extensivement caractérisés. Ces dérivés organométalliques devraient présenter des sections efficaces d’A2P (ainsi que des réponses ONL de troisième ordre) dans le proche-IR bien supérieures à celles de leurs analogues organique. De plus les groupements métalliques redox-actifs devraient permettre d’obtenir des chromophores électro-commutables. Dans cet objectif, les études déjà réalisées sur ces composés joints à l’étude à venir de leur propriétés ONL de troisième ordre et permettra de mieux comprendre les phénomènes electroniques sous-jacents à ces propriétés et le rôle joué par les parties organique et organométalliques de leur structure

Commensality Through a Solar Cult. Ceramics, Social Practices and Symbolism Along the Atlantic Coast (2500-1650 BC)

International audienceThe Bell Beaker phenomenon is characterised by new forms of ritual practices especially known through the studyof Bell Beaker graves. These contexts are linked to the representation of individuals who represent elites of those Neolithicsocieties. Within the complex chiefdoms of the Early Bronze Age, social practices seem to acquire a collective dimension fromwhich new social behaviours emerge. By extension, many domestic ceramic sets display particular organisations related tomeaningful gestures and practices. At this time, the ceramic artefact itself is renewed in terms of forms and ornamentations. Asignificant number of vessels are associated with multiple handles, allowing more complex social interactions. New decorativeschemes can be interpreted as astral (solar and lunar) representations. In Atlantic France, these representations undergo amajor development during the Bronze Age and seem closely linked to ritual and social practices. They carry major symbolicfeatures and the organisation of the scenery, linked to the relationship maintained between the user and the assistants, probablyplays a major role in these collective events. This article will be the occasion to discuss the evolution of these practices, duringparticular and meaningful occasions but also in daily activities

Commensality Through a Solar Cult. Ceramics, Social Practices and Symbolism Along the Atlantic Coast (2500-1650 BC)

International audienceThe Bell Beaker phenomenon is characterised by new forms of ritual practices especially known through the studyof Bell Beaker graves. These contexts are linked to the representation of individuals who represent elites of those Neolithicsocieties. Within the complex chiefdoms of the Early Bronze Age, social practices seem to acquire a collective dimension fromwhich new social behaviours emerge. By extension, many domestic ceramic sets display particular organisations related tomeaningful gestures and practices. At this time, the ceramic artefact itself is renewed in terms of forms and ornamentations. Asignificant number of vessels are associated with multiple handles, allowing more complex social interactions. New decorativeschemes can be interpreted as astral (solar and lunar) representations. In Atlantic France, these representations undergo amajor development during the Bronze Age and seem closely linked to ritual and social practices. They carry major symbolicfeatures and the organisation of the scenery, linked to the relationship maintained between the user and the assistants, probablyplays a major role in these collective events. This article will be the occasion to discuss the evolution of these practices, duringparticular and meaningful occasions but also in daily activities