Abstract: A composition is described which comprises at least one chromium compound, at least one aryloxy compound of an element M selected from the group formed by magnesium, calcium, strontium and barium, with general formula [M(RO)2-nXn]y, in which RO is an aryloxy radical of a derivative ROH containing 6 to 80 carbon atoms, X is a halogen or a hydrocarbyl radical containing 1 to 30 carbon atoms, n is a whole number which may take the values 0 or 1 and y is a whole number in the range 1 to 10, and at least one additive selected from ether type compounds, which may or may not be cyclic, introduced in a near-stoichiometric quantity with respect to the element M.

Abstract: A composition is described which comprises at least one chromium compound, at least one aryloxy compound of an element M selected from the group formed by magnesium, calcium, strontium and barium, with general formula [M(RO)2-nXn]y, in which RO is an aryloxy radical of a derivative ROH containing 6 to 80 carbon atoms, X is a halogen or a hydrocarbyl radical containing 1 to 30 carbon atoms, n is a whole number which may take the values 0 or 1 and y is a whole number in the range 1 to 10, and at least one additive selected from ether type compounds, which may or may not be cyclic, introduced in a near-stoichiometric quantity with respect to the element M.

Abstract: A catalytic composition for oligomerizing ethylene, in particular to 1-hexene, is obtained by mixing at least one chromium carboxylate characterized in that it also contains a free carboxylic acid in a set proportion, with at least one aryloxy compound of an element M selected from the group formed by magnesium, calcium, strontium and barium, with general formula M(RO)2-nXn in which RO is an aryloxy radical containing 6 to 80 carbon atoms, X is a halogen atom or a hydrocarbyl radical containing 1 to 30 carbon atoms and n is a whole number that can take the values 0 or 1, and with at least one hydrocarbylaluminum compound selected from the group formed by tris(hydrocarbyl)-aluminum compounds, chlorinated or brominated hydrocarbylaluminum compounds and aluminoxanes.

Abstract: A catalytic composition is obtained by mixing at least one chromium compound with at least one aryloxy compound of an element M selected from the group formed by magnesium, calcium, strontium and barium, with general formula M(RO)2-nXn, where RO is an aryloxy radical containing 6 to 80 carbon atoms, X is a halogen or a hydrocarbyl radical containing 1 to 30 carbon atoms and n is a whole number that can take values of 0 to 2, and with at least one aluminum compound selected from hydrocarbylaluminum compounds (tris(hydrocarbyl)-aluminum, chlorinated or brominated hydrocarbylaluminum compounds) and aluminoxanes. The catalytic composition can be used in an ethylene oligomerization process, in particular to produce 1-hexene.

Abstract: A catalytic composition for oligomerizing ethylene, in particular to 1-hexene, is obtained by mixing at least one chromium carboxylate characterized in that it also contains a free carboxylic acid in a set proportion, with at least one aryloxy compound of an element M selected from the group formed by magnesium, calcium, strontium and barium, with general formula M(RO)2-nXn in which RO is an aryloxy radical containing 6 to 80 carbon atoms, X is a halogen atom or a hydrocarbyl radical containing 1 to 30 carbon atoms and n is a whole number that can take the values 0 or 1, and with at least one hydrocarbylaluminum compound selected from the group formed by tris(hydrocarbyl)-aluminum compounds, chlorinated or brominated hydrocarbylaluminum compounds and aluminoxanes.

Abstract: A catalytic composition is obtained by mixing at least one chromium compound with at least one aryloxy compound of an element M selected from the group formed by magnesium, calcium, strontium and barium, with general formula M(RO)2-nXn, where RO is an aryloxy radical containing 6 to 80 carbon atoms, X is a halogen or a hydrocarbyl radical containing 1 to 30 carbon atoms and n is a whole number that can take values of 0 to 2, and with at least one aluminum compound selected from hydrocarbylaluminum compounds (tris(hydrocarbyl)-aluminum, chlorinated or brominated hydrocarbylaluminum compounds) and aluminoxanes. The catalytic composition can be used in an ethylene oligomerization process, in particular to produce 1-hexene.

Abstract: Process for liquid-phase hydroformylation of at least one olefin by carbon oxide and hydrogen oxide in the presence of a catalytic composition that contains at least one compound of a transition metal, at least one phosphine oxide, and at least one organic-inorganic salt that does not contain tin or germanium; said salt is a quaternary ammonium salt and/or a quaternary phosphonium salt of general formula Q.sup.+ A.sup.-, in which Q.sup.+ represents an ammonium and/or a quaternary phosphonium and A.sup.- represents an anion. The process applies in particular to internal olefins.

Abstract: A catalyst composition for a process of oligomerising ethylene to produce 1-butene and/or 1-hexene wherein the catalytic composition is obtained by mixing at least one chromium compound with at least one aryloxy aluminum compound with general formula R.sub.n Al(R'O).sub.3-n where R is a linear or branched hydrocarbyl radical containing 1 to 30 carbon atoms, R'O is an aryloxy radical containing 6 to 80 carbon atoms and n is a whole number which can take the values 0, 1 or 2, and with at least one other hydrocarbyl aluminum compound selected from tris(hydrocarbyl)aluminum compounds or chlorinated or brominated hydrocarbyl aluminum compounds.