Polymerization of Tricyclononenes

The expansion of the range of available and reactive monomers allowing preparation of novel polymeric materials, is an actual task of polymer chemistry. This mini-review is devoted to the polymerization of tricyclo [4.2.1.0^2,5]non-7-enes (tricyclononenes) and tricyclo[4.2.1.0^2,5]nona-3,7-dienes (tricyclonona-dienes)–norbornene type monomers containing norbornene and cyclobutane or cyclobutene fragments in the molecules. Their synthesis is carried out using available cyclopentadiene or quadricyclane, which is a product of norbornadiene photo-isomerization. The features of ring-opening metathesis and addition polymerization of tricyclononenes with participation of double bond in the norbornene fragment are highlighted. Examples of the polymerization of a wide range of tricyclononenes with F-, Si-, O-, and N-containing substituents have demonstrated that they are noticeably more active monomers than norbornenes with the same substituents. The main successes have been achieved in the synthesis of F- and Si-substituted polytricyclononenes, which are promising materials for lithography and membrane gas separation.