Anionic Polymerization of 2‐Hexyl[3]dendralene

Abstract In this study, the polymerization behavior of 2‐hexyl[3]dendralene (H3D), which is an alkyl‐group‐derived [3]dendralene, is examined. The polymerization of H3D in tetrahydrofuran (THF) at −78 °C with potassium naphthalenide as the initiator affords poly(H3D) with a narrow molecular weight distribution, although a small shoulder peak is observed at a high molecular weight even before the monomer is completely consumed. The molecular weight distribution of poly(H3D) prepared in heptane is broader than that prepared in THF, indicating that the nucleophilic addition of a propagating carbanion to the carbon–carbon double bond in the polymer chain occurs in addition to polymerization. Furthermore, the microstructure of poly(H3D) is investigated by NMR. Signals corresponding to the conjugate addition structure, that is, 1,4‐ and 4,6‐structures, are exclusively observed. Poly(H3D) prepared in heptane contains a higher content of the 4,6‐structures compared with those prepared in THF.