37 research outputs found
First example of ring carbomer of 1,4-cyclohexadiene
While a series of carbo-mers of 1,3-cyclohexadienes was reported through the use of a specifically developed synthetic strategy, no example of their 1,4-regioisomers was known. Inspired by the methodology elaborated for the preparation of the 1,3-isomers, the synthesis of the first example of carbo-mer of 1,4-cyclohexadiene is presented. Comparison of physico-chemical properties of this first representative with those of the recently described 1,4-regioisomer, especially UV-vis absorption properties, is also addressed
En route to a dianilinyl-substituted carbo-cyclohexadiene with promising electrical properties
The macro-aromatic carbo-benzene core para-disubstituted by 4-anilinyl groups is known to be an efficient single-molecule conductor, exhibiting a conductance of 106 nS measured by the scanning tunneling microscopy-break junction technique. The linear carbo-butadiene analogue bearing the same anilinyl substituents was found to be less efficient, with a conductance of 2.7 nS. The reason of this difference could be elucidated through the study of the charge transport properties of a cyclically locked carbo-butadiene core in a carbo-cyclohexadiene derivative. In this paper, advances in the synthesis of this challenging dianilinyl-substituted carbo-cyclohexadiene are presented
Efficacité de l'association Claventin-Péflacine dans le traitement de premiÚre intention des neutropénies fébriles chimio-induites
MONTPELLIER-BU Pharmacie (341722105) / SudocSudocFranceF
Modélisation de la variabilité spatiale et temporelle des précipitations à la sub-mésoéchelle par une approche multifractale
La reprĂ©sentation de la variabilitĂ© des prĂ©cipitations peut ĂȘtre abordĂ©e sous l angle des statistiques mais les approches usuelles ne sont pas invariantes par changement d Ă©chelle. Des approches alternatives existent : les cascades multifractales, physiquement cohĂ©rentes avec les propriĂ©tĂ©s scalantes de la turbulence (loi de Kolmogorov), permettent la description multi-Ă©chelle de nombreux champs gĂ©ophysiques. Dans cette Ă©tude, nous avons appliquĂ© des outils d analyse multifractale Ă des jeux de donnĂ©es de prĂ©cipitations reprĂ©sentatifs de la variabilitĂ© Ă la sub-mĂ©soĂ©chelle (cartes radar, sĂ©ries pluviomĂ©triques de haute rĂ©solution) et identifiĂ© les gammes d invariance d Ă©chelle dans lesquelles des propriĂ©tĂ©s multifractales prĂ©dominent. Une paramĂ©trisation multifractale robuste vis-Ă -vis de la prĂ©sence de nombreux zĂ©ros dans les enregistrements de pluie a pu ĂȘtre proposĂ©e, ainsi qu un nouvel algorithme de downscaling des prĂ©cipitations respectant cette paramĂ©trisation.Modelling of rainfall variability may be studied in a statistical framework, however usual approaches are not invariant through scale transformations. Alternative tools, such as multifractal cascades, which are physically coherent with scaling properties of turbulence (Kolmogorov s law), enable more pertinent multiscale description of various geophysical fields. In this study, multifractal analysis tools have been applied to rainfall datasets representative of submesoscale variability (radar maps, high-resolution time series). Scaling ranges , i.e. ranges of scales dominated by multifractal symmetries, are identified. We proposed a new multifractal parameterization that is robust to the presence of numerous zeros in rainfall datasets. An original algorithm for disaggregating rain fields is described, based on the latter parameterization.VERSAILLES-BU Sciences et IUT (786462101) / SudocSudocFranceF
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On-board Decision Making Platform for Structural Health Monitoring
International audienceThe ability to monitor the health of complex structures such as aeronautic or civil engineering structures in real time is becoming increasingly important. This process is referred to as structural health monitoring (SHM) and relies on onboard platforms comprising sensors, computational units, communication resources, and sometimes actuators. Many of such platforms have been developed within the last years but there is still a lack of structuration and knowledge exchange regarding the software and hardware architectures of such platforms. The aim of the present paper is to introduce an open hardware and open software platform dedicated to SHM within the fields of aeronautics and civil engineering. The platform presented here will be made available in an open hardware and open source framework to allow SHM researchers to run concurrent detection, localization, classification or quantification algorithms using simple interpreted languages such as Python
N -Cyclopropenio-imidazol-2-ylidene: An N-heterocyclic carbene bearing an N -cationic substituent
International audienceA cationic NHC 1+ bearing an N-bound 2,3-bis(diisopropylamino)-cyclopropenium group is reported. From an easily available dicationic imidazolium precursor, the coordination abilities and stereo-electronic properties of 1+ are evaluated by the formation of Pd(II), Rh(I) and Au(I) complexes. The cationic gold(I) complex is implemented in representative intramolecular Au(I)-catalyzed cyclizations
Synthesis of Functional Carbo-benzenes with Functional Properties: The C2 Tether Key
International audienceBeyond demonstration of conceptual relevance and synthetic feasibility of aryl/alkyl-substituted representatives, carbo-benzene mols. started to gain prospects of broader impact through the emergence of alkynyl derivs. This is first illustrated by examples of di- and hexaalkynyl- carbo-benzenes, a carbo-naphthalene, a carbo-biphenyl, and two carbo-terphenyls. A focus is then given to dialkynyl derivs. by ref. to the peripherally C 2-extruded parents. In the centrosym. quadrupolar series, the C 2expansion or ethynylogation effect is more particularly considered for 9 H-fluoren-2-yl, tris(O- n-alkyl)pyrogallyl, indol-3-yl, 4-anilinyl, and tetraphenyl- carbo-Ph substituents on the following resp. properties: two-photon absorption, chem. stability, columnar mesogenicity, on-surface photoinduced charge sepn. vssingle-mol. conductance, and redn. potential. Topical results and prospects of application are discussed on the basis of crystallog., spectroscopic, and electrochem. analyses vsDFT-calcd. nuclear and electronic structures. For the sake of the discussion consistency, complementary exptl. and computational results are disclosed in the dianilinyl series. Overall, it is shown that combined advances in strategy, protocols, and substrate scope of acetylenic synthesis remain crucial for the development of yet poorly explored but promising types of mol. materials. 1 Introduction 2 Hexaalkynyl- carbo-benzene 3 ortho-Dialkynyl- carbo-benzene 4 para-Dialkynyl- carbo-benzenes 4.1 Bistrimethylsilylethynyl- carbo-benzene 4.2 Bisfluorenylethynyl- carbo-benzene 4.3 Bistrialkoxyarylethynyl- carbo-benzenes 4.4 Bisindolylethynyl- carbo-benzene 4.5 Bisanilinylethynyl- carbo-benzene 5 Carbo-oligo(phenyleneethynylene)s 6 Conclusions