Highly Defined ABC Triblock Cooligomers and Copolymers Prepared by ROMP Using an N‐Heterocyclic‐Carbene‐Substituted Ruthenium Benzylidene Initiator

The “3^rd generation Grubbs” initiator (H₂IMes)(3‐bromopyridine)₂(Cl)₂Ru?CHPh ( 1 ) accomplishes the synthesis of ABC triblock copolymers via living ring‐opening metathesis polymerisation (ROMP) of norbornene derivatives. Complete initiation and an outstanding tolerance of functional groups are provided, which is proven by a combined study by means of matrix‐assisted laser desorption/ionisation mass spectrometry, gel permeation chromatography and NMR spectroscopy on an ABC triblock cooligomer.

Gel permeation chromatograms of oligo A , oligo AB , and oligo ABC .