Photo‐Induced Polymer Cyclization via Supramolecular Confinement of Cyanostilbenes

Abstract

Efficient synthesis of cyclic polymers has received much attention in polymer chemistry field. Although photochemical cycloaddition of terminal p-bonded units provides a plausible way toward cyclic polymerization, it remains challenging to avoid side reactions by manipulating the reaction selectivity. Herein supramolecular confinement has been developed as a promising strategy to address this issue, by introducing highly directional hydrogen bonds to the photoreactive cyanostilbenes. The cyanostilbenes units on both ends of a telechelic macromonomer are orientationally aligned with high local concentrations, yielding [2+2] photo-cycloaddition products upon 430 nm light irradiation. It leads to the formation of cyclic polymers in the self-assembled state, in stark contrast to Z-E isomerization of cyanostilbenes in the monomeric state. Overall, supramolecular confinement effect exemplified in the current study provides new avenues toward cyclic topological polymers with high synthetic efficiency.

Efficient preparation of cyclic polymers via pre-stacking of photo-cycloaddition capable end groups and a continuous-flow technique

“…Photochemistry is a highly attractive preparation method since it allows for fine spatial and temporal control, 20 and a number of different photo-induced cyclizations can be found in the literature. 21–24 Coulembier and Barner-Kowollik et al . 25 reported the first example of catalyst-free photo-induced cyclization, yielding the corresponding cyclic polyesters in nearly quantitative yield.…”

Chirality-Controlled Supramolecular Donor–Acceptor Copolymerization with Distinct Energy Transfer Efficiency

“…Supramolecular polymerization has become an efficient tool to organize molecular building blocks into long-range-ordered nanostructures . In light of the considerable progress made in the monocomponent supramolecular polymerization field, more attention has been paid to multicomponent supramolecular copolymerization systems, which brings advanced functions by increasing the structural complexity. Supramolecular copolymerization of π-conjugated molecules is especially intriguing in this field.…”

Preparation, AIE and ESIPT behaviour, controllable solid-state fluorescence and application of Co2+ probe based on α-cyanostilbene

“…On the other hand, the ever-burgeoning interest in α-cyanostilbene derivatives has heightened their applicative research on functional materials due to the unique AIE characteristic of α-cyanostilbene skeleton [8,11,12,28,[36][37][38][39][40][41]. Nevertheless, the most crucial aspects for fabricating high-performance 'AIE + ESIPT' Schiff base probes based on α-cyanostilbene unite were how to successfully tailor the salicylaldehyde-like structure and legitimately achieve derivatization.…”