Abstract: A lanthanide base olefin polymerization catalyst and its use in polymerization are disclosed. The lanthanide based catalyst is prepared by contacting a lanthanide halide with an ether, then contacting the resulting lanthanide composition with an alkali or alkaline earth metal alkyl compound, and depositing the resulting lanthanide product on a particulate support.

Abstract: Supported catalysts component for producing ethylene-propylene elastomers comprising a compound represented by the formula:(1) [V.sub.3 O(RCO.sub.2) (ED).sub.3 ].sub.2. V.sub.2 O.sub.2 X.sub.6, or(2) V.sub.3 O(RCO.sub.2).sub.6 (ED).sub.3wherein R is alkyl, cycloalkyl, aryl and haloalkyl,wherein R is alkyl, cycloalkyl, aryl and haloalkyl,ED is an electron donor selected from alkyl esters of aliphatic and aromatic carboxylic acid, aliphatic ketones, aliphatic amines, aliphatic alcohols, alkyl and cycloalkyl ethers, and mixtures thereof; andX is selected from Cl--, Br--, Fl-- or RCO.sub.2.sup.--.

Abstract: A highly active anionic polymerization catalyst prepares butadiene polymers having a high 1,4-trans-dienyl content, the catalyst containing an organolithium compound, a barium, strontium or calcium compound, and trialkylaluminum compounds having at least 13 carbon atoms per molecule.

Abstract: Vanadium-arenes [V(arene).sub.2 ] (arene=benzene or mono-, di-, or poly-alkyl-substituted benzene) are obtained, with a high yield, by means of the reduction of a vanadium-arene iodide with zinc, manganese or iron in metal form, or with cobalt di-(cyclopentadienyl).Vanadium-arenes are useful in the preparation of catalyst components active in ethylene polymerization, or in the copolymerization of ethylene in an alpha-olefin.