Preparation of sterically protected 3,4-bis[(2,4,6-tri-t-butylphenyl)phosphinidene]-1,2-bis[4-(4-vinylphenyl)butyl]c yclobutene and its polymers

Two new sterically protected 3,4-diphosphinidenecyclo-butenes, i.e., 1,2-bis[4-(4-methylphenyl)butyl]-3,4-bis[(2,4,6-tri-t-butylphenyl)phosphinidene] cyclobutene, and 3,4-bis[(2,4,6-tri-t-butylphenyl)phosphinidene]-1,2-bis[4-(4-vinylphenyl)butyl]c yclobutene, were prepared. Copolymerization of the latter with styrene was studied. Treatment of [6-(4-vinylphenyl)hex-1-ynyl](2,4,6-tri-t-butylphenyl)phosphine with butyllithium and 1,2-dibromoethane afforded a polymer of the latter cyclobutene.