Construction of Smart Supramolecular Polymeric Hydrogels Cross-linked by Discrete Organoplatinum(II) Metallacycles via Post-Assembly Polymerization

Abstract

Postassembly modification strategy has been successfully employed in the construction of discrete metallosupramolecular assemblies. However, the most known reports have been limited to the simple structural conversion through the easy covalent reactions, thus hindering the development of organometallic functional materials. In this study, we first combined coordination-driven self-assembly and postassembly reversible addition-fragmentation chain-transfer (RAFT) polymerization to produce a new family of star supramolecular polymers containing well-defined metallacycles as cores, which featured typical lower critical solution temperature (LCST) behavior in water because of the existence of poly(N-isopropylacrylamide) (PNIPAAM) moieties. Moreover, the obtained star polymers could further form supramolecular hydrogels cross-linked by discrete hexagonal metallacycles at room temperature without heating-cooling process. Interestingly, the resultant polymeric hydrogels exhibited stimuli-responsive behavior toward temperature and bromide anion as well as self-healing property. We demonstrated that the dynamic nature of Pt-N bonds in the hexagonal metallacycles played an important role in determining the stimuli-responsive and self-healing property of the final soft matters. Thus, merging coordination-driven self-assembly and postassembly polymerization provided a new avenue to the preparation of functional materials containing well-defined, discrete metal-organic assemblies as main scaffolds.

Metal Organic Polyhedra: A Click‐and‐Clack Approach Toward Targeted Delivery

“…toward metal catalysts or harsh reaction conditions) supramolecular frameworks. [ ][ ][ ][ ] To date, only a handful examples of the PAM of MOPs have been reported . For example, Stang and co‐workers first demonstrated the use of the strain promoted alkyne‐azide click (SPAAC) [ ][ ][ ] reaction to functionalize preformed self‐assembled metallacycles.…”

Encoding, Reading, and Transforming Information Using Multifluorescent Supramolecular Polymeric Hydrogels

“…The hydrogels used in this study are shown in Figure . They consist of a poly(acrylamide) (pAAm) network cross‐linked by N,N ′‐methylenebis(acrylamide) (MBAAm), as well as tethered tetracationic macrocyclic anion receptors and pendant alkyl sulfonate subunit (hydrogel G0 ; nonfluorescent).…”

Construction of Pillar[5]arene Tetramer‐Based Cross‐Linked Supramolecular Polymers through Hierarchical Charge‐Transfer and Host‐Guest Interactions

“…In view of this, and based on our research interest in bridge pillar [5]arenes synthesis, [34][35][36][37][38] herein, we designed a novel pillar [5]arene tetramer via charge transfer interactions and hierarchically to construct cross-linked supramolecular polymers. [39][40][41] First we synthesized two different pillar [5]arene dimers, decorated with naphthalene diimide bridged pillar [5]arene (NDI-P), naphthalene bridged pillar [5]arene (NAP-P), and neutral guest (NG) possessing two 5-(1H-1,2,3-triazol-1-yl) pentanetrile binding sites ( Figure 2). By taking advantage of the strong affinities of pillar [5]arene with neutral guests firstly, we confirmed the interaction between (NDI-P) and (NAP-P) with (NG) as shown in (Figure 1) which just gave linear supramolecular polymers.…”