Significantly Red‐Shifted Emissions of Nonconventional AIE Polymers Containing Zwitterionic Components

Abstract

Nonconventional luminescence polymers without any aromatic structures have attracted great interest from researchers due to their special structure and excellent biocompatibility. However, these materials mostly emit in the blue or green region, in which preparation of materials with long-wavelength (especially near-infrared) emission is still a great challenge. In this work, it is found that 2-(dimethyl amino) ethyl methacrylate (DMA) and itaconic anhydride (ITA) undergo a ring-opening reaction at room temperature, and subsequently generate zwitterionic compound (IDMA). Based on the clustering-triggered emission (CTE) mechanism, ionic bond can effectively promote the isolated electron-rich chromophores to form new emissive clusters with extended electron delocalization. Herein, two oligomers (P1 and P2) with different fluorescence emissions by controlling the concentration of zwitterionic monomers before polymerization are synthesized. It is worth noting that the maximum emission wavelength of P2 at high concentration is up to 712 nm, which is very rare in previous reports. In addition, the resulting oligomer (P2) shows typical aggregation-enhanced emission (AEE), excitation-dependent fluorescence, temperature-sensitive emission, and solvatochromism. The cytotoxicity assay demonstrates that P2 was low toxic to Huh7 and LM3 cells, and suitable for cell imaging. This research provides the possibility for rational molecular design and the feasibility of luminescence regulation.

A Novel L-Shaped Fluorescent Probe for AIE Sensing of Zinc (II) Ion by a DR/NIR Response

“…Due to its essential biological role, many AIE-based fluorescence sensors for Zn 2+ ion have been developed and applied [ 14 , 18 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 ]. A metal cation can induce a fluorescence turn-on of the AIE probe dissolved in solution by different mechanisms: primarily, the formation of emissive aggregates (cleavage-triggered aggregation, CTA).…”

Bathochromic-Shifted Emissions by Postfunctionalization of Nonconjugated Polyketones

“…They found that copolymers such as poly­(maleic anhydride- co - N -vinyl-2-pyrrolidone) (PMVP), poly­[(1-octene)- co -(itaconic anhydride)] (POITA), poly­(itaconic anhydride- co -vinyl caprolactam) (PIVC), and poly­(itaconic anhydride- co -vinyl pyrrolidone) (PIVP) exhibited significantly bathochromic-shifted emissions compared to the blue emission of the corresponding homopolymers. Qiao reported that poly­[(maleic anhydride)- alt -(vinyl acetate)] derivatives and their emissions could realize blue-to-red transformation by a simple heat treatment or changing the pH value of the solution. , Guo reported significantly bathochromic-shifted emissions of zwitterionic copolymers by increasing the ionic bond/hydrogen bond interactions on the polymer chains . These contributions provide a strategy to achieve bathochromic-shifted emission of NTIL polymers by enhancing through-space charge transfer between side chains to form new emissive clusters (Figure C).…”

“…40,41 Guo reported significantly bathochromic-shifted emissions of zwitterionic copolymers by increasing the ionic bond/hydrogen bond interactions on the polymer chains. 42 These contributions provide a strategy to achieve bathochromic-shifted emission of NTIL polymers by enhancing through-space charge transfer between side chains to form new emissive clusters (Figure 1C). Very recently, Bao developed well-defined styrenic donor polymers grown from a traditional acceptor (naphthalene diimide) for continuous color tuning by through-space charge transfer between the side chain donor and the traditional acceptor.…”

Metal Cation-Responsive and Excitation-Dependent Nontraditional Multicolor Fluorescent Hydrogels for Multidimensional Information Encryption

“…8 In addition, due to the formation of clusters with different degrees of n−π* and/or π−π* interactions, NLPs exhibit EDF behavior. 40 Up to now, very less attention has been paid to the fabrication of nontraditional fluorescent hydrogels (NTFHs). 41,42 Moreover, to our best knowledge, no multicolor FPHs for information encryption have been constructed by NLPs.…”

“…The close contact of the nontraditional chromophores in the aggregates/clusters leads to the overlap of intra and/or intermolecular electron clouds, forming an extended conjugation of n−π* and/or π–π* interactions, i.e., through-space conjugation (TSC), which generates fluorescence emissions . In addition, due to the formation of clusters with different degrees of n−π* and/or π–π* interactions, NLPs exhibit EDF behavior …”