Max Ratier

Moisture content and extractive materials in maritime pine wood by low field 1H NMR

Summary The low field 1H NMR relaxometry technique has been shown to be effective in determining the qualitative and quantitative moisture content and the water state distribution in maritime pine wood (Pinus pinaster Ait). Further investigations on extractive materials in resin-rich samples evinced the presence of oleoresin components, which may disturb adhesion on pine wood boards.

Time-domain 1H NMR characterization of the liquid phase in greenwood

Abstract The time domain of 1H NMR spectroscopy allows straightforward editing of the T 2 relaxation profiles in maritime pine wood. A new method from the Carr-Purcell-Meiboom-Gill sequence is proposed to measure the amount and distribution of water in wood, as well as the location of major dissolved organic materials. A general calibration model giving reliable and precise identification of these parameters is described. The method presented for editing T 2 relaxation profiles (obtained by the Contin program) may be helpful in solving practical drying and gluing problems in the wood industry. It can be used for monitoring chemical modifications of wood fibers involved in the design of wood composite materials.

Sulfones organostanniques: synthese et reactivite des trialkystannyl-1 para-toluenesulfonyl-2 acetylenes

Abstract The preparation and some reactions of 1- para -toluenesulfonyl-2-(trialkylstannyl)acetylenes are desribed. The compounds undergo addition to a number of conjugated dienes, whereas ene adducts, owing to low enophilic reactivity cannot generally be obtained. Desulfonylation reactions give rise to a variety of vinyltin derivatives.

Flash Vacuum Thermolysis of Terpenic Compounds in the Pínane Series

Abstract The flash pyrolysis of various derivatives (hydrocarbons and oxygenated compounds) in the pinane series has been studied. We observed a high degree of conversion and good selectivity.

Thermal Decomposition of Organotin Sulfamates: A One Pot Synthesis of Vinyltributyltin Compounds

Abstract The preparation of some alkyltributyltin sulfamates is described. Thermal decomposition of these compounds provides a route to vinyltributyltin derivatives.

Synthèse et thermolyse éclair d'esters α-tributylstanniques

Abstract The preparation of some alkyltributyltin acetates and thiocarbonates is described. Flash thermolysis of these compounds at high temperature (600-950°C) and under a moderate vacuum, provides a new route to vinyltributyltin derivatives.

A fast algorithm for computer simulations in INEPT experiments

A rapid, convenient and portable computer simulation program based on the general INEPT equations is described. It allows an easy calculation of the spectra for any weakly coupled structure up to nine systems of spins-12 [ca 25 spins] and an optimization of the experimental polarization and refocusing time parameters.

Quaternary ammonium halides2-tributylstannylpropanol: an efficient cyclotrimerization catalyst system for aromatic isocyanurate synthesis

Abstract α-Organotin alcohols and quaternary ammonium salts, when used jointly, present a very high activity for the trimerization of aromatic isocyanates. If used separately, no catalytic activity is observed.

Double stannylation d'un sulfure propargylique par l'hydrure de tributyletain en presence de thiol

Abstract In the presence of small amounts of p -thiocresol, hydrostannylation of propargyl p -tolyl sulfide promotes the unexpected formation of ( Z )-1,2-bis(organostannyl)olefin instead of yielding normal addition products. The application of a non-refocusing INEPT pulse sequence in 119 Sn NMR spectroscopy allows the determination of its stereochemistry by comparison of observed patterns with calculated spectra.

Hydrostannation of Methyl (Carboxysulfamoyl) Triethylammonium Hydroxide Inner Salt: A New Route to Tributyltin Isocyanate

Abstract A synthetically useful and facile method for the synthesis of tributyltin isocyanate is described.