Abstract: Organometallic compounds, as exemplified by trimethylaluminum, can be purified by recrystallization from a solvent by cooling. The organometallic compound is first dissolved in a solvent forming a solution and the purified organometallic compound is then recrystallized, under cooling conditions, from the solvent.

Abstract: Polymethylaluminoxane compositions having increased solution stability in organic solvent and, in some cases, increased polymerization activity, which comprise moieties derived from an organic compound containing an electron-rich heteroatom (e.g., from Group V and/or Group VI of the Periodic Table) and a hydrocarbyl moiety. These compositions can be formed by reaction of trimethylaluminum, the organic compound, and water. They can also be formed by reaction of pre-formed polymethylaluminoxane the organic compound, which can be a hydrocarbyl group-containing compound containing an electron-rich heteroatom (e.g., oxygen, nitrogen, or sulfur), either with or without an active hydrogen atom connected to the heteroatom. The organic compound, in some embodiments, has also been found to be effective in increasing the catalytic activity of modified polymethylaluminoxane which, in addition to methyl, contain C.sub.2 and higher alkyl groups for enhanced solution stability.

Abstract: Polymethylaluminoxane compositions having increased solution stability in organic solvent and, in some cases, increased polymerization activity, which comprise moieties derived from an organic compound containing an electron-rich heteroatom (e.g., from Group V and/or Group VI of the Periodic Table) and a hydrocarbyl moiety. These compositions can be formed by reaction of trimethylaluminum, the organic compound, and water. They can also be formed by reaction of pre-formed polymethylaluminoxane the organic compound, which can be a hydrocarbyl group-containing compound containing an electron-rich heteroatom (e.g., oxygen, nitrogen, or sulfur), either with or without an active hydrogen atom connected to the heteroatom. The organic compound, in some embodiments, has also been found to be effective in increasing the catalytic activity of modified polymethylaluminoxane which, in addition to methyl, contain C.sub.2 and higher alkyl groups for enhanced solution stability.

Abstract: The efficient production of alkylaluminoxane by the reaction of water, e.g., in the form of atomized water, and trialkylaluminum, e.g., trimethylaluminum, in an organic solvent medium can be achieved using a preformed alkylaluminoxane as a reaction moderator in the reaction mixture.

Abstract: Aluminoxanes can be produced by contacting an organic solvent containing a trialkylaluminum compound with an atomized spray of water. If desired, a pore-formed aluminoxane can be present as a reaction moderator.

Abstract: Trimethylaluminum can be formed by reacting a methylaluminum chloride, such as dimethylaluminum chloride, with sodium in the presence of an effective amount of an alkali or alkaline earth metal fluoride (e.g., sodium fluoride) to enhance the reaction.

Abstract: Dimethylzinc is prepared by heating a dimethylaluminum halide, e.g., dimethylaluminum chloride, and a dialkylzinc, e.g., diethylzinc, with distillative removal of dimethylzinc from the reaction mixture which results therefrom.