摘要:
The invention relates to a novel process for the preparation of acyl isocyanates which consists in reacting oxalyl chloride with an N-trialkylsilylcarboxamide or an N,N-bis(trialkylsilyl)carboxamide. The process makes it possible to obtain acyl isocyanates in good yield, in particular acyl isocyanates derived from aliphatic amides, and under simplified reaction conditions.
摘要:
The invention concerns the synthesis of silicone by anionic polymerisation of cyclic organosiloxane oligomers in the presence of a slightly nucleophilic strong base. The invention aims at providing novel strong base catalysts, more efficient in terms of solubility in the silicones, with hydrolysis stability strength and polymerising capacity. To achieve this, the invention provides for the use of ylides derived from aminophosphonium such as for example that of formula: [Me3N)3P—CHMe2]+, MeO or derived from phosphoranylidenes such as that of formula: [Me3P—HC=Pme3]+, t-BuO. The invention also concerns strong base catalysts as novel products.
摘要:
The disclosure concerns a directional hydrophonic antenna, consisting of several pairs of dipoles formed by omnidirectional hydrophones superimposed in a streamer and keeping the same reference angle for all the pairs of dipoles. The goal sought is achieved by means of a chain of superimposed, directional modules each bearing a hydrophonic sensor on each lateral face and joined by ringed tubular elements through which there goes a central rod made of fiber glass and a strand of electrical connection cables.
摘要:
Methods are provided for the catalytic hydroamination of compounds having an alkyne or allene functional group, in which the compound is contacted with ammonia or an amine in the presence of a catalytic amount of a gold complex under conditions sufficient for hydroamination to occur.
摘要:
A subject of the present invention is new compounds having a lanthanide and having a tridentate ligand, a process for their preparation and their use in particular as polymerization catalysts.
摘要:
The invention relates to new compounds having an element of group 12 and having a tridentate ligand, a process for their preparation and their use in particular as a polymerization catalyst.
摘要:
Novel compounds having one group 13 element bound with one mono- or di-anionic tridentate ligand, a method of preparation thereof and use thereof as a copolymerization catalyst.
摘要:
Stable, bent allenes, organometallic complexes of bent allenes are provided along with methods of conducting chemical processes such as olefin metathesis, comprising contacting an olefin substrate with an organometallic complex as described herein, under suitable conditions.
摘要:
An X-ray machine is provided. The X-ray machine comprises an X-ray tube; an X-ray detector placed opposite the X-ray tube in a direction of emission of X-rays; and a mobile device on which the X-ray tube and the X-ray detector are mounted, the mobile device comprising a motor capable of causing the automatic movement of the X-ray machine, and an impact-sensing system coupled to the motor in order to control the movement of the mobile device in the event of an impact applied to the X-ray apparatus.
摘要:
The present invention provides novel and stable crystalline 1H-1,2,3 triazolium carbenes and metal complexes of 1H-1,2,3 triazolium carbenes. The present invention also provides methods of making 1H-1,2,3 triazolium carbenes and metal complexes of 1H-1,2,3 triazolium carbenes. The present invention also provides methods of using 1H-1,2,3 triazolium carbenes and metal complexes of 1H-1,2,3 triazolium carbenes in catalytic reactions.