Spontaneous Multicomponent Polymerization of Imidazole, Diacetylenic Esters, and Diisocyanates for the Preparation of Poly(β-aminoacrylate)s with Cluster-Induced Emission Characteristics

Abstract

Multicomponent polymerization (MCP) is an efficient and rapid method for obtaining multifunctional polymeric materials that have been widely developed in recent years. In this work, poly­(β-aminoacrylate)­s were obtained by spontaneous MCP with the assistance of the C2-amidation of 1-methylimidazole together with diacetylenic esters and diisocyanates. This process can be carried out under mild conditions, such as in a catalyst-free and room-temperature environment. Through the systematic optimization of the polymerization conditions, the resultant poly­(β-aminoacrylate)­s could have molecular weights of up to 24 100 g/mol and excellent yields (up to 94%). All the polymers were well-characterized by gel permeation chromatography (GPC), nuclear magnetic resonance (NMR), and Fourier transform infrared spectroscopy (FT-IR), and all the collected data illustrated that the polymerization mechanism corresponds to a model reaction of small molecules. The photophysical property of these obtained polymers indicated that one of the polymers (polymer P1b2a) demonstrated a luminescence capability that was unconventional because no fluorescent emitters were present in its main chains or side chains. A further study suggested that the clustering of diverse subgroups with subsequent electron cloud overlapping, which resulted in molecular conformation rigidification, was primarily responsible for this emission. Thus, the current MCP method will provide guidance for preparing new nonconjugated polymers with cluster-induced emissive functional materials for easily tailored specific applications.

Catalyst‐Free Multicomponent Cyclopolymerizations of Diisocyanides, Activated Alkynes, and 1,4‐Dibromo‐2,3‐Butanedione: a Facile Strategy toward Functional Polyiminofurans Containing Bromomethyl Groups

“…[ 53,54 ] The large number of ester groups in P1c2b3 were gathered together to form through‐space conjugation of isolated π‐electron clouds with increasing concentration, leading to the cluster luminescence. [ 27,55 ] However, the PL intensity began to decrease when the concentration of P1c2b3 exceeded 1.0 × 10 −3 mol L −1 due to cluster groups exceeding the optimal size for cluster luminescence. [ 54 ] In addition, with the excitation wavelength ranging from 370 to 490 nm, P1c2b3 exhibited excitation‐dependent luminescence behavior, as shown in Figure S14 (Supporting Information).…”

Functional Heterochain Polymers Constructed by Alkyne Multicomponent Polymerizations

“…[ 36 ] In 2020, a spontaneous MCP of diacetylenic esters, diisocyanates, and imidazole for the construction of poly(β‐aminoacrylate)s with high molecular weights ( M w up to 24 100) in excellent yields (up to 94%) and a high‐atom economy manner was reported ( Figure A). [ 37 ] Notably, the polymerizations could proceed efficiently under mild conditions, such as catalyst‐free and room temperature.…”

“…Reproduced with permission. [ 37 ] Copyright 2020, American Chemical Society. B) Synthesis of structure‐ and sequence‐controlled polyheterocycles by MCP of diynes, diamines, and formaldehyde.…”

“…Reproduced with permission. [ 37 ] Copyright 2020, American Chemical Society. C) Water contact angle of (left) P 8 and (right) P 9 .…”

pH and thermo responsive aliphatic tertiary amine chromophore hyperbranched poly(amino ether ester)s from oxa‐Michael addition polymerization

“…[ 6,7 ] In comparison with conventional fluorescent polymers, the unconventional fluorescence polymers without traditional chromophores have attracted a great deal of interest because of their facile preparation, excellent water solubility and good biocompatibility. [ 8–22 ] Among of unconventional fluorescent compounds, tertiary amine chromophore polymers with intrinsic fluorescence and stimulus responsiveness, which have proved to be an effective biomedical application materials and been extensively studied. [ 23–28 ]…”