Anionic Polymerization of 2‐Hexyl[3]dendralene

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.