Molecular systems that can prepare copolymers by incorporating monomers A and B in a consistent alternating fashion, poly(A-alt-B), are rare. Our group has demonstrated that metal alkylidene complexes (M = Mo or W) featuring bulky aryloxide and pyrolide ligands are suitable initiators for the formation of tactic copolymers. We are currently exploring the differences between molybdenum and tungsten as polymerization initiators, as well as the possibility of post-polymer modifications.