Thermoelectric generators enable the direct conversion from heat into electrical power whatever the nature of the heat source. Therefore, they provide an effective route to use waste heat originating from automobiles, incinerators and so on, to produce clean electrical power. Until the very recent years, the main drawback of these systems has been their poor energy conversion efficiency that made them unsuitable for widely used applications. However, a great effort of research has been devoted in the past decade to the development of novel materials with improved performances. Consequently, the annual number of submitted patents that deal with thermoelectric conversion systems or thermoelectric materials has grown very rapidly. The efficiency of a thermoelectric material used for power generation increases with the so-called dimensionless figure of merit ZT defined as ZT = S²T/rl, where S is the Seebeck coefficient or thermopower, r the electrical resistivity, and l the thermal conductivity. It is generally considered that a figure of merit higher than unity is required for efficient thermoelectric energy conversion. ZT=1 for both p type and n type materials of an ideal thermoelectric device would allow for example a 10% recovery of the heavy trucks exhaust gas waste energy. In recent years, several families of materials with ZT>1 have been developed, including for example skutterudites, magnesium silicides…, and it has been demonstrated that thermoelectric modules based on these materials can reach about 10% efficiency. However, there is still a need of more efficient thermoelectric materials which would enlarge the number of possible applications or open new markets. During the 1990s and 2000s, oxychalcogenides materials with general formula RCuChO (R = trivalent cation, Ch = S, Se or Te) have been widely studied first as possible parent compounds for new high-Tc superconductors and then as potential p-type transparent conducting materials for optoelectronic applications, mostly in the thin film form. In the beginning of 2008, an intense research activity emerged dealing with the study of a new family of superconductors: the iron-oxypnictides. Following the discovery of superconductivity in these materials, we initiated an exploratory research in this field. We were the first to show that these materials not only exhibit, beside fascinating superconducting properties, promising thermoelectric properties. Their Seebeck coefficient can be larger than 120 µV.K-1 around 100K and they exhibit good electrical properties. As a matter of fact, we have shown that their electrical transport properties, in the liquid nitrogen temperature range, are not far from those of the best materials known to date based on BiSb alloys. Following this discovery, we have expanded our study to the oxychalcogenides family, and we have shown that these materials exhibit very promising thermoelectric performances in the 400-650°C temperature range and that they could be used in mid-temperature thermoelectric energy converters. The main topic of this project is to study the thermoelectric properties of oxychalcogenides materials in order to assess their potential as p-type thermoelectric materials and to optimize them for applications in thermoelectric modules.

The project detailed in this proposal deals with asymmetric organic transformations using chiral d transition metal- and lanthanide-based catalysts. We hypothesize that enolates can add to unactivated olefins in an enantioselective fashion, using bimetallic activation. To achieve this goal, we reason that a lanthanide complex can be used as strong sigma-Lewis acid to activate the carbonyl functionality of a pronucleophile and generate an enolate (or a complexed enol), while a soft pi-Lewis acid, incorporating for instance gold or platinum, activates the olefin toward nucleophilic attack. The chirality could be borne by either complex. The result of such a reaction would be comparable to an asymmetric Michael addition, yet applied to simple alkenes. The development of this reaction would pave the way for total syntheses of natural products.

Fierce competition in today's global market forces industrial companies to better design and manage their supply chain networks. In particular, making the right decisions regarding one of the core supply chain processes, goods production, directly affects the productivity and hence the competitiveness of a company. Industrial production management involves, among others, deciding about which products should be made, when and in which quantity. Despite its rather simple definition, production planning is most often a complex task for industrial managers who can be overwhelmed by the complexity of the problem. This is particularly the case when production planning involves lot-sizing and scheduling decisions. This arises whenever start-up operations such as tool changes are required between production runs of different products on a machine. In this situation, finding the right quantity to produce after a start-up, i.e. the lot size, requires reaching a good trade-off between start-up costs (indicating large lot sizes) and inventory holding costs (indicating small lot sizes) . Lot-sizing and scheduling leads to the formulation of difficult combinatorial optimization problems. A wide variety of solution techniques from the Operations Research field have been proposed to solve them. The scientific challenge here is to develop optimization methods in which the production system is modelled with the required accuracy and which are capable of providing guaranteed optimal or near-optimal production plans within reasonable computation times. In this context, project LotRelax focuses on: (i) improving the production system representation in the optimization method by taking into account a complicating feature frequently encountered in practice: the presence of sequence-dependent start-up costs and times, (ii) computing guaranteed optimal or near-optimal production plans by exploiting recent theoretical advances in the mathematical programming field, in particular the latest developments in semidefinite programming. Semidefinite programming can be broadly described as the extension of linear programming from the space of real vectors to the space of symmetric matrices. This rather new area of mathematical programming has witnessed important developments during the last twenty years and has proved successful at solving prominent difficult combinatorial optimization problems. However, as can be seen from recent reviews in the academic literature, there seems to be no previous attempt at using semidefinite relaxations to solve lot-sizing and scheduling problem. The main objective of project LotRelax is thus to develop solution approaches based on semidefinite relaxations to solve several variants of lot-sizing problems involving sequence-dependent start-up costs and times.

Asymmetric intramolecular olefin hydroamination allows an atom economic synthesis of chiral nitrogen heterocycles that are building blocks for numerous natural products. Recently several lanthanide complexes have been reported as enantioselective catalysts of a test cyclisation/hydroamination, but there are to date no efficient catalysts for performing the reactions under mild conditions and for giving rise to satisfactory activities and enantioselectivities for a wide range of compounds. We have prepared a new family of enantioselective catalysts for intramolecular hydroamination, differing in their structures from formerly described catalysts. These catalysts are lanthanide anions coordinated by two binaphthylamine ligands, associated to alcaline cations. These complexes allow the preparation of pyrrolidines and a piperidine with asymmetric inductions similar to those reported in the literature. The aim of our project is the optimisation of the catalysts in terms of activity and asymmetric inductions and to widen the scope of the methodology to the preparation of new alkaloid analogues for the synthesis of biologically valuable molecules as an ultimate goal. One part of the project is the synthesis of various lanthanide complexes coordinated by two binaphthylamine ligands and their evaluation as enantioselective catalysts for the formation of pyrrolidines and piperidines. As these catalysts are easily tunable, the influence of the nitrogen substituents, of the lanthanide nature and of the alkaline cation will be studied. Other chiral diamine ligands will also be investigated. Mechanistical studies will be realised by synthetic and spectroscopic approaches and by DFT calculations. After optimisation of the catalysts, their application scopes will be examined in order to access chiral functionalised nitrogen-containing heterocycles. Studies on the size of the cycle and the influence of the substituents of the double-bond of the substrate on the activity and enantioselectivity of the reaction will be carried out. Finally, the synthesis and screening of new heterocycles of biological relevance using asymmetric hydroamination reactions as the key-step will be realised. A library of constrained analogues of catecholamines will be prepared from diversely substituted benzylamines and screened by biological tests. The study of new asymmetric domino reactions will be realized with the aim to synthesize new analogues of cytotoxic alkaloids. The strategy is to initiate the reactions by asymmetric intramolecular hydroamination followed by an addition on a conjugated acceptor. These reactions will be applied to the synthesis of analogues of Camphothecin or Yohimbane that will be further tested for their anti-tumor activity. The knowledge of the Laboratoire de Catalyse Moléculaire in enantioselective catalysis and in the chemistry of lanthanides should allow a rapid improvement of the first results. Investigations in this laboratory will be devoted to the optimization of catalysts, the preparation of various substrates and the determination of enantiomeric excesses. The preparation and characterization of lanthanide complexes will be realized with the collaboration of the team of Dr Trifonov (Nizhny Novgorod, Russia), well known in this field. The Laboratoire de Chimie Structurale Organique will work on the evaluation of enantiomeric excesses and on mechanistical studies that will be realised also with the collaboration of Pr Calhorda (Lisbon, Portugal) for calculations. The expertise of the Laboratoire des Procédés et de Synthèse des Substances Naturelles is crucial for the synthesis of sophisticated substrates and for the application of asymmetric hydroamination reactions to the synthesis of valuable molecules, a task never realised to the best of our knowledge. The collaboration with the Institut Curie and the French national chemical librairies will allow the biological screening of our molecules. These common skills should contribute to the success of this green chemistry project and to the valorisation of atom economic reactions. Optimisation of lanthanide-catalysed asymmetric hydroamination is crucial for the synthesis of biologically active nitrogen-heterocycles by economic and sustainable processes.

NMR spectroscopy has proved to be a unique tool for probing structure and dynamics in a wide range of molecular assemblies. Continuous methodological developments, combined with the breakthroughs which have been accomplished in probe and spectrometer hardwares have led to a variety of high-resolution experiments that have paved the way for an accurate measurement of large ensembles of spin interactions. These observables are particularly useful to constrain the most sophisticated simulations, allowing to describe complex chemical species and processes at an atomic level. Unfortunately, in most of the systems that are of interest to the scientific community nowadays, the size or the complexity of the molecular architecture which is probed often leads to overcrowded spectra whose resolution is too low to give access to their analytical content. Neither the use of very high field spectrometers, nor the development of pulse sequences that combine broadband and selective irradiations have allowed to fully address this problem. In this context, we have recently proposed to develop an original concept which consists in carrying out a parallel acquisition of different experiments using a single-receiver-coil system. We have successfully shown that this approach could be applied to run different selective echoes in different parts of an NMR sample, leading to a spin-spin coupling edition of the interaction network around a selected spin nucleus. Following up these encouraging results, the research proposal aims at providing NMR spectroscopists with a novel generation of correlation experiments based on a sample spatial frequency encoding. First, a set of simulation programs will be developed, that will target the evaluation of the NMR signal, based on the analytical calculation of the evolution of spin coherences, which results from a gradient encoded pulse sequence. Second, capitalizing on this theoretical tool, we will then focus on the methodological development of new, high-resolution correlation techniques inspired by this sample gradient encoding concept. Third, since gradient encoded spectroscopy is intrinsically less sensitive than standard NMR experiments, we will aim at exploring several techniques as potential alternatives to improve sensitivity. Among them, we will notably study in what extent the use of para-hydrogen as a polarizing agent is compatible with our experimental schemes. Our ultimate goal will be to apply the high-resolution sequences that will result from this work to address challenging systems : these sequences will first be incorporated into a structural analysis protocol that will be applied to determine the stereochemistry of synthetic oligosaccharides. Then, we will evaluate the ability of the gradient encoded selective refocusing (G-SERF) spectroscopy to simplify enantiomeric visualization when it is applied to enantiomeric mixtures dissolved in chiral liquid crystals. Finally, we will focus on quantitativity (which is an essential issue in analytical chemistry), in the frame of an accurate evaluation of enantiomeric excesses.