LES SELS METALLIQUES D'ACIDES FORTS CONSTITUENT UNE NOUVELLE CATEGORIE D'AMORCEURS DE POLYMERISATION CATIONIQUE. LE TRIFLUOROMETHANESULFONATE D'ALUMINIUM, REPRESENTANT TYPIQUE DE CETTE FAMILLE, MONTRE UNE TRES GRANDE ACTIVITE CATALYTIQUE QUI NE SE LIMITE PAS A L'AMORCAGE DE LA POLYMERISATION MAIS S'ETEND EGALEMENT AUX REACTIONS ELECTROPHILES. LE SESQUITRIFLATE D'ETHYLBORE, COMPOSE TOUT A FAIT ORIGINAL A UNE STRUCTURE PORTEE ET NON SYMETRIQUE. IL AMORCE TRES EFFICACEMENT LA POLYMERISATION DE MONOMERES N ET PI DONNEURS.

ACTIVITE CATALYTIQUE EN POLYMERISATION CATIONIQUE DES SELS METALLIQUES DU TYPE MTBN OU MTBN-M (M'TXN')M. ESSAIS DE CES SELS, ET PLUS PARTICULIEREMENT DES PERCHLORATES ET DES TRIFLUOROMETHANE SULFONATES DE METAUX VIS-A-VIS DE MONOMERES ALIPHATIQUES, AROMATIQUES ET HETEROCYCLIQUES. APPROCHE DES MECANISMES REACTIONNELS D'AMORCAGE EN MILIEU HETEROGENE ET HOMOGENE, SOIT PAR VOIE PUREMENT CHIMIQUE, SOIT PAR SPECTROSCOPIE ET CONDUCTIMETRIE. ACTIVITE DE CES NOUVEAUX AMORCEURS DANS LES REACTIONS ELECTROPHILES DU TYPE ACYLATION, ESTERIFICATION ET ALKYLATION

LE TRAVAIL PRESENTE DANS CETTE THESE TRAITE DE L'ETUDE DE CATALYSEURS SUPPORTES POUR LA POLYMERISATION CATIONIQUE DES OLEFINES. NOUS AVONS ETUDIE DEUX TYPES DE CATALYSEURS SUR SILICE. SELON LA VOIE DE SYNTHESE CHOISIE, DEUX GRANDES CLASSES DE CATALYSEURS D'ACIDITE DE LEWIS DIFFERENTE SONT OBTENUES. LA PREMIERE CLASSE DE CATALYSEURS PREPAREE A L'AIDE DES ALKYLALUMINIUMS EST TRES EFFICACE POUR LA POLYMERISATION CATIONIQUE DE L'ISOBUTENE. NOUS AVONS, DANS CE CAS, ETE AMENES A DEVELOPPER UN MECANISME DE POLYMERISATION PRENANT EN COMPTE LA STRUCTURE DES CATALYSEURS. LA SECONDE CLASSE DE CATALYSEURS PREPAREE A PARTIR DES HALOGENURES METALLIQUES EST UTILISEE PRINCIPALEMENT POUR L'OLIGOMERISATION DES OLEFINES. L'ACTIVITE DE CES CATALYSEURS NE SE LIMITE PAS A LA POLYMERISATION MAIS S'ETEND AUSSI AU CADRE DES REACTIONS ELECTROPHILES COMME L'ALKYLATION DES AROMATIQUES QUE NOUS AVONS ETUDIEE. ENFIN, UN DEVELOPPEMENT DE CE TRAVAIL A ETE INITIE AVEC L'ETUDE DES CATALYSEURS SUPPORTES SUR CHLORURE DE MAGNESIUM

This book, cohesively written by an expert author with supreme breadth and depth of perspective on polyurethanes, provides a comprehensive overview of all aspects of the science and technology on one of the most commonly produced plastics. Covers the applications, manufacture, and markets for polyurethanes, and discusses analytical methods, reaction mechanisms, morphology, and synthetic routes Provides an up-to-date view of the current markets and trend analysis based on patent activity and updates chapters to include new research Includes two new chapters on PU recycling and PU hybrids, covering the opportunities and challenges in both

In less than 20 years N-heterocyclic carbenes (NHCs) have become well-established ancillary ligands for the preparation of transition metal-based catalysts. This is mainly due to the fact that NHCs tend to bind strongly to metal centres, avoiding the need of excess ligand in catalytic reactions. Also, NHC‒metal complexes are often insensitive to air and moisture, and have proven remarkably resistant to oxidation. This book showcases the wide variety of applications of NHCs in different chemistry fields beyond being simple phosphine mimics. This second edition has been updated throughout, and now includes a new chapter on NHC‒main group element complexes. It covers the synthesis of NHC ligands and their corresponding metal complexes, as well as their bonding and stereoelectronic properties and applications in catalysis. This is complemented by related topics such as organocatalysis and biologically active complexes. Written for organic and inorganic chemists, this book is ideal for postgraduates, researchers and industrialists.

Each chapter of Phosphorus Compounds: Advanced Tools in Catalysis and Material Sciences have been carefully selected by the editors in order to represent a state-of-the-art overview of how phosphorus chemistry can provide solutions in various fields of applications. The editors have assembled an international array of world-renowned scientists and each chapter is written by experts in the fields of synthetic chemistry, homogeneous catalysis, dendrimers, theoretical calculations, materials science, and medicinal chemistry with a special focus on the chemistry of phosphorus compounds. Phosphorus Compounds: Advanced Tools in Catalysis and Material Sciences is of interest to a general readership ranging from advanced university course students to experts in academia and industry.

Organic matter and soil productivity; Turnover of plant residues; Mineralization of organic compounds; Dynamics of organic forms of nitrogen; Nitrogen economy; Biodegradation of organic matter; Biochemical transformation of organic matter; Bitumens in soil organic matter; Characterization of humic acids; Carbon dating; Modern techniques and their implact on soil organic matter research; Sludge; Soil organic matter components and plant metabolism; Interaction between agrochemicals and organic matter; Peat.