Polymetalated 1-alkyne compositions

A hydrocarbon soluble polymetalated 1-alkyne catalyst for anionic polymerizations comprising the reaction product of a 1-alkyne, an organometallic compound R.degree.M, and a 1,3-conjugated diene wherein R.degree. is a hydrocarbyl group, M is an alkali metal, the mole ratio of conjugated diene to 1-alkyne is at least about 2:1, and the reaction is conducted at a temperature of at least about 70.degree. C.

A hydrocarbon soluble polylithiated 1-alkyne catalyst for anionic polymerizations comprising a reaction product of a 1-alkyne, an alkyl lithium compound containing from about three to about 10 carbon atoms in the alkyl group, and a 1,3-conjugated alkadiene wherein the mole ratio of lithium compound to 1-alkyne is about 2:1 to about 4:1, the mole ratio of conjugated alkadiene to 1-alkyne is from about 8:1 to about 20:1, the 1-alkyne is characterized by the formula

• RCH.sub.2 --C.tbd.CH (III)
• wherein R is hydrogen or an aliphatic group containing from 1 to about 6 carbon atoms, and the reaction is conducted at a temperature of from about 70.degree. C. to about 150.degree. C.

A method of preparing a hydrocarbon soluble polymetalated 1-alkyne catalyst for anionic polymerizations which comprises the steps of (a) reacting in a hydrocarbon solvent, a 1-alkyne with an organometallic compound R.degree.M in a mole ratio of about 1:2 to about 1:4, wherein R.degree. is a hydrocarbyl group and M is an alkali metal to form an intermediate, and (b) reacting said intermediate with a 1,3-conjugated diene at a temperature of at least about 70.degree. C. wherein the mole ratio of conjugated diene to 1-alkyne is at least about 2:1.