摘要:
A process for separating dioxygen from a gaseous mixture containing dioxygen, which entails:a) absorbing dioxygen by one or more transition metal complexes at a low oxidation state of the formula (A):(L.sub.n (M.sup.+p).sub.m (X.sup.-z).sub.x.sup.mp-xz (A) the absorption causing formation of a peroxo dihapto deoxygenated product complex of the formula (B):(L.sub.n '(M.sup.p+2 O.sub.2).sub.m' (X.sup.-z).sub.x).sup.m'p-x'z(B)b) desorbing oxygen from the complex by electrochemically oxidizing the peroxo dihapto product complex obtained by reaction of the complex of the formula (A) wiht O.sub.2 : andc) recovering the absorbed oxygen.
摘要:
An organic material for non-linear optics comprising:an electron donor group constituted by a heteroaromatic cycle;an electron attractor group selected from NO.sub.2 and CN; andan electron effect transmitter group selected from an aromatic system of the phenyl ring type, or a chain having n atoms of carbon including a double or a triple bond (n
摘要:
An organic material for non-linear optics, in which the structure of the molecule includes an electron donor group and an electron attractor group connected by means of an electron-transmitting group, the material being characterized by the fact that it satisfies the formula: ##STR1## where R is selected from (CH.sub.3).sub.2 N and CH.sub.3 O, with the first material being dimethylamino 4, cyano 4' biphenyl and the second being methoxy 4, cyano 4' biphenyl.
摘要:
Processes for the preparation of monoisocyanates, diisocyanates or polyisocyanates of the present invention are described which comprises reacting monomeric or oligomeric primary amines or diamines, and carbon monoxide at atmospheric pressure in the presence of a catalytic amount of a compound or a complex of a divalent metal selected from palladium, nickel and platinum, and in the presence of stoichiometric or catalytic quantities of benzoquinone as an oxidant. Isocyanates are produced in high yields and purities. They can be isolated as free isocyanates or as blocked isocyanates by in situ reaction with blocking agents that contain an active hydrogen being attached to oxygen, sulfur or nitrogen. Monoisocyanates and diisocyanates serve as chemical, agricultural or pharmaceutical intermediates. Diisocyanates and polyisocyanates are used to produce polyurethanes, polyureas, polyisocyanurates and related polymers.
摘要:
The process includes an electrochemical reduction, under carbon dioxide atmosphere, of benzyl type ArCH.sub.2 X or ArCH(CH.sub.3)X halogenides.According to the invention, the process consists of operating in the presence of a catalyst containing at least one organometallic complex derived from a transition metal combined with a bidentate or tetradentate coordinate.