Synthesis of metallosupramolecular polymers incorporating cage silsesquioxanes in the main chains

We first time prepared main‐chain type cage octasilsesquioxane (T₈) containing coordination polymers based on transition metal complexes with a bis‐Schiff base T₈ ligand ( bis‐SA‐T ₈ ), which was prepared from para‐bis(3‐aminopropyl)hexaisobutyl‐substituted T₈ cage ( bis‐T ₈ ) with salicylaldehyde. A mono‐Schiff base T₈ ligand ( SA‐T ₈ ) was prepared from 3‐aminopropylheptaisobutyl‐substituted T₈ cage ( mono‐T ₈ ) with salicylaldehyde. Coordination of bis‐SA‐T ₈ with Cu²⁺ and Zn²⁺ in a solution as well as the film state was confirmed by the d–d transition appearing as broad shoulder on the longer wavelength at around 600 nm and the fluorescence at around 440–470 nm, respectively. The resulting metallosupramolecular polymers gave optically transparent films in the visible region by a casting method. However, opaque green and whitish films were obtained in the case of the Cu²⁺ and Zn²⁺ complexes with SA‐T ₈ , respectively. The thermal stabilities of the metallosupramolecular polymers were higher than those of the corresponding metal complexes of SA‐T ₈ . © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 2260–2266