Summary: Ethylene and butadiene were copolymerized with a silylene‐bridged bis(fluorenyl) complex {[Me2Si(C13H8)2]NdCl} ( 1 ) in combination with various alkylating agents (BuLi/AlH(iBu)2, (Bu)MgCl, Mg(Bu)(Oct)). Copolymers have a unique microstructure since they contain 1,2‐cyclohexane rings and unsaturations along the polymer chain. An intramolecular mechanism was proposed for the formation of six‐membered rings. The influence of these cyclic structures on thermal properties of the copolymers has been investigated.