Process for preparing or purifying Group III-A organometallic compounds

Claim 1

A process for preparing a product having the formula: M.sup.1 R.sub.a wherein M 1 is an element of Group III-A of the Periodic Table; each R is independently selected from hydrogen, hydrocarbyl, and combinations thereof; and a is 3; said product having total volatile metal compound impurities of less than 1 ppm; comprising the steps of: A. forming a nonvolatile intermediate compound having the formula: {M.sup.1 R.sub.(a+1) }.sup.-.sub.b {M.sup.2 }.sup.+b wherein M 1 is a Group III-A element, M 2 is selected from elements of Groups I-A and II-A of the periodic Table and ammonium, a is three, b is selected from 1 or 2, each R is independently selected from hydrocarbyl, hydrogen and combinations thereof, and said intermediate compound includes volatile organometallic impurities, B. distilling the major production of said volatile organometallic impurities away from said intermediate compound, leaving a residue of said volatile organometallic impurities mixed with said intermediate compound, C. decomposing said intermediate compound according to the following reaction: c{M.sup.1 R.sub.(a+1) }.sup.-.sub.b {M.sup.2 }.sup.+b +dM.sup.1 X.sub.a →eM.sup.1 R.sub.a +fM.sup.2 X.sub.b wherein c, d, e, and f are integers selected to balance the equation and X is an anion; thereby providing said M 1 R a mixed with said residue, and D. postdistilling said MR a mixed with said residue from the liquid state, thereby selectively distilling said residue out of said MR a ; whereby said product contains less than one ppm of said residue.