Abstract: Process for the preparation of 1-hexane consisting in effecting the oligomerization of ethylene in the presence of a catalyst comprising a vanaduim complex having the formula: (arene)2 VX wherein the term arene represents benzene or mono-, di-, or tri-alkylsubstituted benzene, V is a vanaduim ion with a low wxidation state, and X is an anion selected from non-coordinated anions such as B(Ar)4—, AlCl4—, carboxylates and sulfonates.

Abstract: A “bridged” bis-cyclopentadienyl complex which can be advantageously used for the formation of a catalytic system active in the (co)polymerization of ethylene and other &agr;-olefins is represented by means of the following formula (II): wherein: M represents a metal selected from titanium, zirconium or hafnium; A′ and A″ each independently represent an anion containing an &eegr;5-cyclopentadienyl ring coordinated to M; R′ or R″ each independently represents a group of an anionic nature &sgr;-bound to the metal M; B represents an unsaturated bivalent organic residue having from 1 to 30 carbon atoms, bound, respectively, to the ring of group A′ and to the —CH2-methylene group by means of carbon atoms.

Abstract: A process is described for regenerating exhausted zeolitic catalysts containing titanium and deriving from oxidation processes of organic substrates with hydrogen peroxide. Said process consists in carrying out a treatment in an aqueous medium with hydrogen peroxide in the presence of inorganic fluorinated compounds, subsequent to thermal treatment of the exhausted catalyst.

Abstract: A process for separating hydrocarbon isomers in gas phase on molecular sieves, including feeding mixtures of hydrocarbon isomers to a primary adsorption column configured to adsorb isomers with a greater selectivity towards the molecular sieves, feeding effluent from the primary adsorption column to a secondary adsorption column configured to adsorb remaining isomers with a greater selectivity towards the molecular sieves and discharge a stream containing isomers with a lower selectivity towards the molecular sieves, feeding desorbing agent to a desorption column configured to discharge a stream containing isomers with a greater selectivity towards the molecular sieves and the desorbing agent, feeding the stream from the secondary adsorption column to a distillation unit configured to recover the desorbing agent for recycling to the desorption column, feeding the stream from the desorption column to another distillation unit configured to recover the desorbing agent for recycling to the desorption column.

Abstract: The invention relates to the use of organic carbonates having formula (I) 1

Abstract: Process for the preparation of 2,6-dimethylnaphthalene comprising reacting with at least one aromatic hydrocarbon, in the presence of a zeolitic catalyst, a mixture of naphthalenes comprising a cut obtained by the fractionation of suitable petrochemical streams and subsequent treatment of the product thus obtained with a solid acid.

Abstract: A process is described for the preparation of polycarbonate dials (PCD) with a high molecular weight comprising two subsequent reaction steps, wherein in the first step PCD with a molecular weight ranging from 500 to 2000, is synthesized and in the second step the molecular weight of the PCD is increased to the desired value. Polycarbonate diols are usefully applied in the field of thermoelastomeric polyurethane manufactured products, paints, adhesives and synthetic leather.

Abstract: Process for the production of diaminodiphenylmethane and its higher homologues products, which comprises reacting aniline, or one of its derivatives, and formaldehyde, or a compound capable of producing formaldehyde under the reaction conditions, in the presence of a zeolite in acid form having a spaciousness index ranging from 2.5 to 19.

Abstract: A process for producing a linearly-miniaturized, densified optical product, which entails a) cold filling a mould with a liquid colloidal dispersion formed from a chemical precursor; b) polycondensing the liquid colloidal dispersion to obtain a gel; c) supercritically drying the gel to form an amorphous aerogel having dimensions corresponding to the mould; and d) isotropically miniaturizing the amorphous monolithic aerogel obtained.

Abstract: Process for the separation of 2,6-dimethylnaphthalene from mixtures containing it, comprising the following operations:

Abstract: Process for preparing catalytic systems consisting of:

Abstract: Process for the polymerization of unsaturated vinyl and/or vinylidene monomers which comprises reacting one or more monomers in the presence of heterocyclic initiators having a nitrogen atom bound to an oxygen atom at a temperature ranging from 100 to 130° C.

Abstract: Mass-continuous process for the production of vinylaromatic polymers which comprises feeding a reaction mixture containing at least one vinylaromatic monomer to at least one tubular reactor of the PFR type and operating with a recycling ratio, referring to the recycling flow-rate/feeding flow-rate, of less than 4.

Abstract: Process for the preparation of end-products based on vinylaromatic polymers with a predominantly syndiotactic structure which comprises: a) compressing the polymer in powder form in a mould at a pressure ranging from 0.1 to 500 Mpa; b) sintering the compressed powder, under pressure, at a temperature ranging from the glass transition temperature of the polymer (Tg) to 150° C.; c) slowly cooling the end-product to room temperature.

Abstract: The present invention relates to a process for the preparation of catalysts suitable for the transposition reaction of oximes to amides. The process consists in englobing submicronic particles of MFI-type zeolites in a siliceous ligand substantially inactive in the above reactions.

Abstract: A process is described for the preparation of polycarbonate diols (PCD) with a high molecular weight comprising two subsequent reaction steps, wherein in the first step PCD with a molecular weight ranging from 500 to 2000, is synthesized and in the second step the molecular weight of the PCD is increased to the desired value. Polycarbonate diols are usefully applied in the field of thermoelastomeric polyurethane manufactured products, paints, adhesives and synthetic leather.

Abstract: A “bridged” bis-cyclopentadienyl complex which can be advantageously used for the formation of a catalytic system active in the (co)polymerization of ethylene and other a-olefins is represented by means of the following formula (II): 1

Abstract: A continuous process is described for the preparation of olefin oxides by direct epoxidation of an olefin with hydrogen peroxide, or compounds capable of producing hydrogen peroxide under the reaction conditions, in a solvent medium, in the presence of a catalytic system consisting of a zeolite containing titanium and a buffer system with a pH controlled within the values of 5.5 to 8.0, consisting of a nitrogenated base and a salt thereof with an organic or inorganic acid. The process allows high conversions and selectivities of the olefin into the corresponding oxide with a catalytic activity stable over a period of time.

Abstract: Catalyst for steam cracking reactions consisting of pure mayenite having the general formula:

Abstract: A method is described for improving the catalytic performances of titanium silicalite having formula (I) by the activation of the catalyst (I) in an aqueous medium with hydrogen peroxide, in the presence of precursors of fluoride ions or anionic species containing fluorine. The activated catalyst (I) is particularly useful in oxidation processes with hydrogen peroxide of organic substrates and, in particular, in hydroxylation reactions of aromatic compounds, amoximation reactions of carbonyl compounds, epoxidation reactions of olefinic compounds and oxidation reactions of nitrogenated compounds.