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Cyclohexene oxide (CHO) is a useful building block for the synthesis of novel materials and is a model substrate for polymerization catalyst development. The driving force for CHO polymerization is derived from its bicyclic structure, which combines the release of the enthalpy from epoxide ring-opening (ca. −15 kcal/mol) and a twist-chair-to-chair conformation shift in the cyclohexane ring (ca. −5 kcal/mol) upon enchainment. The lack of regio-defined functional handles attached to the CHO monomer limits the ability to both pre- and post-functionalize the resultant materials and establish structure–property relationships, which reduces the versatility of currently accessible materials. We report the synthesis of two series of CHO derivatives with butyl, allyl, and halogen substituents in the α and β positions relative to the epoxide ring. Adding substituents to the CHO ring was found to affect polymerization kinetics, with 4-substituted (β) CHO being more reactive than 3-substituted (α) CHO analogs when initiated with a mono(μ-alkoxo)bis(alkylaluminum) pre-catalyst. Polymer thermal properties depended on substituent location and identity. Halogenated CHO rings were most reactive and produced the highest glass transition temperatures in the resultant polymers (up to 105 °C). Density functional theory revealed a possible mechanistic explanation consistent with the observed differences in polymerization rate for the 3- and 4-substituted CHOs derived from a combination of steric and thermodynamic considerations. 

We report a series of redox-active bis(pincer) Pd( ii ) complexes in which the redox active units are based on either a diarylamido or a carbazolide framework. Compounds 1 and 2 contain two full diarylamido/bis(pincer) PNP units connected either via an Ar–O–Ar linker ( 1 ) or an Ar–Ar bond ( 2 ). Compound 3 is a fused bis(pincer) where the two PNP units share an aromatic ring. Compound 4 is built around an indolo[3,2- b ]carbazole core in which two NNN pincers share an aromatic ring similarly to 3 . These metal complexes all display two reversible oxidation waves with the Δ E values increasing in the order of 1 < 2 < 4 < 3 . The same trend in increasing electronic coupling emerges from the analysis of the IV-CT bands in the NIR portion of the optical spectra. The analysis of these compounds was further advanced by data from EPR spectroscopy, X-ray diffractometry, and DFT calculations. It is concluded that the monooxidized cations 2+–4+ belong to Class III on the Robin-Day classification of mixed-valence compounds. Compound 4 possesses enforced near-planarity that enables delocalization of the unpaired electron in 4+ across a broader conjugated system compared to 3+ .