Preparation of poly[(1,1-dipropyl)butane-1,4-diyl], (Pr2CCH2CH2CH2)n, via regiospecific ring opening polymerisation of 3,3-dipropylcyclobutene

Abstract

A general route to 3,3-disubstituted cyclobutenes is described and 3,3-dipropylcyclobutene is subjected to ring opening metathesis polymerisation (ROMP) using the Schrock initiator, Mo(CHR)(NAr)(OR′)₂, where R is C₆H₅C(Me)₂-, Ar is 2,6-diisopropylphenyl and R′ is (Me)₃C- to give a polymer which is completely regiospecific (HT) and stereospecific (trans); the polymer is reduced to poly[(1,1-dipropyl)butane-1,4-diyl], which shows evidence of unusual properties associated with the conformational control exerted by the quaternary centres.