Alkene metathesis is a superb methodology. We report the progress using alkene metathesis in the synthesis of polymeric organic semiconductors. Three classes of polymers have been synthesized using acyclic diene metathesis (ADMET) or ring opening metathesis polymerization (ROMP), viz., poly(acetylene)s (PA), poly(arylene‐vinylene)s (PAV), and organometallic polymers. For PAs, ROMP of cyclooctatetraenes is best, whereas for PAV, both ADMET and indirect and direct ROMP are viable. Metathesis performs flawlessly with the correct monomers, as molybdenum and particularly the robust Ru carbenes demonstrate. When performing ROMP, one is often rewarded with structurally uniform polymers that can display very low polydispersities. Overall, metathesis is a powerful tool for the preparation of semiconducting polymers.

Three derivatives of 4,7-substituted [2.2.2]paracyclophane-trienes were synthesized and used in ring-opening metathesis polymerization (ROMP), resulting in well-soluble poly(para-phenylenevinylene)s (PPV). The paracyclophane-trienes were prepared using an iterative buildup of a phenylene–ethynylene backbone, followed by a cis selective Grignard reduction and an intramolecular McMurry reaction. The monomers were applied in ROMP to result in well-soluble PPV derivatives with an unusual substituent pattern. The PPVs were spin-coated into amorphous, highly fluorescent films. To the best of our knowledge, we are the first to synthesize 4,7-substituted [2.2.2]paracyclophane-trienes and use them as ROMP monomers.

The synthesis of two 4,7,12,15-tetrakisalkoxy-substituted [2.2.2]-paracyclophane-1,9,17-trienes and their polymerization employing ring opening metathesis polymerization (ROMP) using Ru-carbenes (third-generation Grubbs catalyst) is reported. Phenylene ethynylene trimers are reduced via a Grignard reagent, followed by an intramolecular McMurry cyclization to give the cyclophenes. The cyclophenes are polymerized into soluble poly(para-phenylene vinylene)s (PPV), which are analyzed in solution by NMR, UV-vis, and fluorescence spectroscopy. They are spin coated into amorphous, fluorescent thin films, and investigated by optical spectroscopy and cyclic voltammetry.

Poly(para-phenylene vinylene) (PPV) and its derivatives are important semiconducting polymers for organic electronics. Herein, an alkene metathesis approach to obtain PPVs is reported. Tri(iso propyl)silyl-substituted norbornadienes are employed as solubilizing agents. As PPV precursors divinylbenzene is used for acyclic diene metathesis and paracyclophane diene for a ring-opening metathesis polymerization-type approach. The resulting polymers are analyzed by gel permeation chromatography (GPC), UV-vis, fluorescence, and nuclear magnetic resonance (NMR) spectroscopy. All of the polymers show good solubility in common solvents.

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