Recent advances in oligomers/polymers with unconventional chromophores

Abstract

Unorthodox chromophores enjoy the advantages of better hydrophilicity, large structural diversity, low-cost and facile synthesis, high chain flexibility and good biocompatibility compared to conventional chromophores, leading to many applications.

Synthesis of thermoresponsive nonconjugated fluorescent branched poly(ether amide)s via oxa-Michael addition polymerization

“…[1][2][3][4] Compared with conventional fluorescent polymers, nonconjugated polymers containing unconventional chromophores possess many advantages, such as facile preparation, environmental friendliness, excellent water solubility, and good biocompatibility. [5][6][7][8] Over the past few decades, a series of fluorescent polymers without conventional chromophores, including polyamidoamine, [9][10][11][12][13][14] poly(amino ester), 15,16 polyethyleneimine, 17,18 polysiloxanes, 19,20 polyurea, 21 polyamides, 22 polyesters, 23 polycarbonate, 24 poly(N-vinylpyrrolidone)s, 25 and so on, [26][27][28][29][30][31][32] have been synthesized and studied, finding that their intrinsic fluorescence properties stem from unconventional chromophores such as aliphatic amines, carbonyl, ester, or amide groups.…”

Revisiting an ancient inorganic aggregation‐induced emission system: An enlightenment to clusteroluminescence

“…[ 28–32 ] Typical clusteroluminescent molecules such as natural cellulose, polysaccharide, polypeptide, proteins, and some artificial polymers generally are nonconjugated and only comprise some sp3 carbon‐connected heteroatoms or amide groups. [ 33–36 ] In spite of their nonconjugated molecular structures, they show bright visible emission once they are clustered to form aggregates. By comparing these organic cellulose or polysaccharide with the previously mentioned inorganic luminescent system like europium(II) chloride, it is obvious they show some similarities: (1) they all lack typical chromophore defined by traditional molecular photophysics; (2) they all exhibit AIE characteristic which are not emissive in dilute solution but brightly emissive in visible region when clustered or aggregated; (3) their luminescence properties mostly correlate closely with their aggregate characteristics such as morphology and alignment.…”

“…[28][29][30][31][32] Typical clusteroluminescent molecules such as natural cellulose, polysaccharide, polypeptide, proteins, and some artificial polymers generally are nonconjugated and only comprise some sp3 carbon-connected heteroatoms or amide groups. [33][34][35][36] In spite of their nonconjugated molecular structures, they show bright visible emission once they are clustered to form aggregates. By comparing these organic cellulose or polysaccharide with the previously mentioned inorganic luminescent system like europium(II) chloride, it is obvious they show some similarities: (1) they all lack typical chromophore defined by traditional molecular photophysics;…”

Tunable Photoluminescence Properties of Microcrystalline Cellulose with Gradually Changing Crystallinity and Crystal Form

“…Recently, nonconventional luminogens with persistent room temperature phosphoresce (p-RTP) are attracting increasing attention owing to their fundamental significance and diverse technical applications in optoelectronic and biomedical aspects. [1][2][3][4][5][6][7][8][9][10][11] These luminogens normally enjoy the merits of DOI: 10.1002/marc.202100321 good hydrophilicity, facile preparation, environment-friendliness, and outstanding biocompatibility, which render them highly suitable for biological and medical applications. [1][2][3][4][5][6][7][8][9][10][11][12] Despite different p-RTP systems like Xylitol, [1] -poly-L-lysine ( -PLL), [3] sodium alginates (SA), [4] polyacrylamide (PAM), [5] sodium polymethacrylate (PMANa), [6] D-(+)-xylose, [7] cyanoacetic acid, [8] and hydantoin [9] were reported, p-RTP of nonaromatic luminogens still remains at its infancy stage, [10][11][12][13] their emission mechanism remains a controversial issue, meanwhile, various assumptions one following close on another.…”

“…[1][2][3][4][5][6][7][8][9][10][11] These luminogens normally enjoy the merits of DOI: 10.1002/marc.202100321 good hydrophilicity, facile preparation, environment-friendliness, and outstanding biocompatibility, which render them highly suitable for biological and medical applications. [1][2][3][4][5][6][7][8][9][10][11][12] Despite different p-RTP systems like Xylitol, [1] -poly-L-lysine ( -PLL), [3] sodium alginates (SA), [4] polyacrylamide (PAM), [5] sodium polymethacrylate (PMANa), [6] D-(+)-xylose, [7] cyanoacetic acid, [8] and hydantoin [9] were reported, p-RTP of nonaromatic luminogens still remains at its infancy stage, [10][11][12][13] their emission mechanism remains a controversial issue, meanwhile, various assumptions one following close on another. [14][15][16] Among them, the clustering-triggered emission (CTE) mechanism has received more and more recognition, [17][18][19][20][21][22]…”