Ring-opening metathesis polymerization (ROMP) of norbornene macromonomer using Mo(CHCMe 2Ph)(NAr)(OR) 2 as the initiator

Abstract

Efficient polymerization of norbornene macromonomer bearing a ring-opened poly(norbornene) substituent has been accomplished by the ring-opening metathesis polymerization by the well-defined Schrock-type molybdenum initiator, Mo(CHCMe 2Ph)( N-2,6- i Pr 2C 6H 3)(OCMe(CF 3) 2). The key steps for the macromonomer synthesis are: (i) selective end capping of ring-opened poly(norbornene) with p-Me 3SiOC 6H 4CHO; (ii) exclusive hydrolysis of the SiMe 3 group; and (iii) esterification of OH group produced at the end of preformed polymer chain with norbornene carboxylic acid chloride. Mo(CHCMe 2Ph)( N-2,6- i Pr 2C 6H 3)(OCMe(CF 3) 2) was found to be an effective initiator in order for this polymerization to proceed to the complete conversion.