Synthesis of conjugated segment-based cyclic polymers for direct imaging of the cyclic molecular topology

Abstract

Conjugated polyacetylene-based monocyclic and bicyclic polymers were synthesized by blocking-cyclization metathesis polymerization using the short ladderphanes as the intial motif and multi-cyclizing unit, and fully characterized to elucidate the cyclic...

Cyclic–hanging-multicyclic polymer synthesized by ladderphane-mediated blocking-cyclization technique for the direct visualization of cyclic macromolecular topology

“…The blocking-cyclization technique 29–31 was performed well via successive ROMPs of the difunctional monomer BNP , a mixture of monofunctional monomer TNP and macromonomer NB ( c - PPMT ), and finally bifunctional BNP to afford a cyclic–hanging-multicyclic polymer c -{ PBNP n -[ b - P ( TNP m – k - co - NB ( c - PPMT ) k )] 2 - b - PBNP n } (Scheme 1). It is noteworthy that the last formed short ladderphane PBNP was used as a cyclization unit to ensure the formation of a cyclic structure via multiple reactions, which can avoid a residue of the linear polymer precursor.…”

“…Lately, we established a new strategy with a ringopening metathesis polymerization (ROMP)-based blockingcyclization technique for the readily synthesis of monocyclic, bicyclic, and tricyclic polymers, 29 and especially the preparation of multicyclic polymers was achieved by the blockingcyclization technique through precisely designing the starting norbornene monomers with different functionalities. 30,31 In contrast to the traditional methods for synthesizing cyclic polymers, this method possesses some prominent features, including the direct use of the commercial catalyst, permitting a relatively high monomer concentration, the availability of a cyclic structure with high purity and without the treatments of separation and purification of the linear polymer precursor, owing to using the short ladderphane as the multiple cyclizing unit. 29,32 However, how to develop an efficient route for the synthesis of multicyclic polymers with a complex cyclic topology and plenty of cyclic macromolecular units remains a great challenge, and the direct visualization of cyclic molecular topology was still rarely realized.…”

Facile synthesis of monocyclic, dumbbell-shaped and jellyfish-like copolymers using a telechelic multisite hexablock copolymer

“…[34][35][36][37][38] As is well documented, some biomacromolecules including proteins and nucleic acids can undergo well-controlled self-folding to form assemblies with hierarchically ordered architectures. [39][40][41][42][43][44] Inspired by this intriguing biological phenomenon, a wide range of synthetic polymers have been rationally designed and subjected to intramolecular cross-linking to fold into defined architectures, in which macrocycle-bearing self-folding poly-mers primarily include monocyclic, bicyclic, and multicyclic polymers and their derivatives, [45][46][47][48][49][50][51][52][53][54] and single-chain nanoparticles with tunable sizes and shapes (i.e., tadpole and dumbbell) contain at least one intrachain folding block formed by a one-step, stepwise or orthogonal folding process. [55][56][57][58][59][60][61][62][63] To our surprise, more complex intracyclic folding nanoparticles have been scarcely reported.…”

“…The backbone of JFPs can be further extended to twin cycles and more complex folding multicycles (i.e., θ, α, β, γ, and δ and their hybrid forms) in a broad sense. [45][46][47][48][49][50][51][52][53][54] Thus far, JFPs comprising a bicyclic, multicyclic or intracyclic folding backbone have not been achieved although they are important members of JFPs.…”

“…, θ, α, β, γ, and δ and their hybrid forms) in a broad sense. 45–54 Thus far, JFPs comprising a bicyclic, multicyclic or intracyclic folding backbone have not been achieved although they are important members of JFPs.…”