Supramolecular Polymeric Radicals: Highly Promoted Formation and Stabilization of Naphthalenediimide Radical Anions

Abstract

The supramolecular polymeric radicals are developed to promote the generation efficiency and stability of naphthalenediimide (NDI) radical anions. To this end, a water‐soluble bifunctional monomer bearing two naphthalene‐viologen end groups and a NDI center is designed and synthesized. The supramolecular polymeric NDI radical anions are fabricated on the basis of host–guest complexation between the NDI‐containing bifunctional monomer and cucurbit[8]uril (CB[8]) and followed by the photoinduced electron transfer process under UV light irradiation. The electrostatic effect of CB[8] and the bulky and rigid structure of supramolecular polymer are combined to stabilize the excited state of NDIs and NDI radical anions, contributing to the high enhancement of the formation of NDI radical anions with excellent stability. It is found that the highest occupied molecular orbital energy and lowest unoccupied molecular orbital energy of NDI are also lowered by the formation of supramolecular polymer. In addition, the supramolecular polymeric NDI radical anions could be utilized as a supramolecular photoreducing agent to reduce cytochrome C with a higher efficiency. It is anticipated that other radicals can also be stabilized through this strategy, and this line of research may lead to the development of novel polymeric radical materials.

Surfactant-induced chirality transfer, amplification and inversion in a cucurbit[8]uril–viologen host–guest supramolecular system

“…S20 (ESI†), the diffusion coefficient of L4/0.67SDS was slightly larger than that of the L4/0.67SDS/0.67CB[8] mixture ( D L4/0.67SDS = 2.00 × 10 −10 m 2 s −1 , D L4/0.67SDS/0.67CB[8] = 1.62 × 10 −10 m 2 s −1 ), indicating that the introduction of CB[8] interacting with the remaining free viologen in L4/0.67SDS changed the state of the original assembly and led to the formation of larger assemblies. 64 In addition, we investigated the time-dependent morphological changes of binary and ternary supramolecules by TEM characterization. It was found that the change morphological trajectories of L4/0.67SDS (Fig.…”

Through-Space Conjugated Supramolecular Polymer Radicals from Spatial Organization of Cucurbit[8]uril: An Efficient Approach for Electron Transfer and Smart Photochromism Materials

“…A cucurbit[8]­uril (Q[8] or CB[8]) host is a larger homologue of the Q­[ n ]­s family, which not only can accommodate and stabilize V •+ radicals in the confined cavity ,− but also distinguishes itself by encapsulating V 2+ derivative guests as the electron-accepting moiety and an electron-donating guest to form a host-enhanced charge-transfer complex in its rigid space. − In addition, Q[8] as the host can also simultaneously include two homo guests, such as arylpyridinium or naphthalene, which can be dimerized inside the cavity to form highly stable Q[8]-enhanced π–π complexes under the macrocyclic confinement effect. ,− Evidently, these results indicate that the confined space of the Q[8] cavity has the excellent advantages of strengthening the weak intermolecular interactions and controlling the orientation of the two encapsulated guests. However, to the best of our knowledge, V •+ radicals that are directly triggered by the Q[8]-confined space via intermolecular PET have not yet been studied …”

“…However, to the best of our knowledge, V •+ radicals that are directly triggered by the Q [8]-confined space via intermolecular PET have not yet been studied. 32 In this work, as a proof-of-concept model, N,N′-bis(4carboxylphenyl)-4,4′-bipyridinium (BcpV 2+ 2Cl − ) was designed as the guest to bind with the Q [8] host (Scheme 1a). As shown in Scheme 1b, Q [8] could trigger the BcpV 2+ guest to form linear J-type polymers by simultaneously accommodating two terminal carboxylphenyl groups of the guest in its cavity.…”

Supramolecular Radical Switches Regulated by Host‐Guest Chemistry

“…Recently, CB[ n ]s have been widely used in radical chemistry, such as regulating the generation of radicals, [ 11 ] enhancing the stability of radicals, [ 12 ] improving the catalytic activity of free radicals, [ 13 ] and constructing responsive materials. [ 14 ] However, reports on using CB[ n ]s to regulate the generation of free radicals from water‐soluble thermal initiators were lacking.…”