Synthesis and self-assembly of tetraphenylethene and biphenyl based AIE-active triazoles

Abstract

Self-assembly of fluorescent functional materials has attracted increasing interest in the fabrication of optoelectronic and biological nanodevices. Tetraphenylethene (TPE) is a typical dye molecule with aggregation-induced-emission (AIE) characteristics. Melding TPE carrying triple-bond functionality with diazide-containing biphenyl through ''click'' chemistry generates AIE-active luminogens [1,1 0biphenyl]-4,4 0 -diyl bis(6-(4-(4-(1,2,2-triphenylvinyl)phenyl)-1H-1,2,3-triazol-1-yl) hexanoate) [1(5)] and [1,1 0 -biphenyl]-4,4 0 -diyl bis(11-(4-(4-(1,2,2-triphenylvinyl)phenyl)-1H-1,2,3-triazol-1-yl) undecanoate) [1(10)] with solid state efficiencies up to unity. Slow addition of dilute THF solutions of 1(m) (m ¼ 5, 10) into nonsolvents such as n-hexane and water yields self-assembled white wooly solids. TEM and SEM observations reveal the (helical) nanofibrous structure of the aggregates. Upon cooling from their concentrated hot solutions, 1(m) readily precipitate. Meanwhile, they can also form gels at high concentrations. Both precipitates and gels of 1(m) exhibit structures similar to those of the aggregates formed in nonsolvents. These results indicate that 1(m) can facilely self-assemble into high emission efficiency (helical) nanofibers, thus paving the way for their optoelectronic and biological applications.Chart 1 Chemical structure of 1(m) (m ¼ 5, 10).Scheme 1 Synthetic route to 1(m) (m ¼ 5, 10).

Self‐Assembly of Aggregation‐Induced‐Emission Molecules

“…Tang et al. showed that biphenyl‐based triazoles can also be used as a spacer for nanofiber formation . It should be noted that as the van der Waals forces bring the molecules together, other possible interactions may also occur between the self‐assembled molecules.…”

“…[33] Ta ng et al showedt hat biphenyl-based triazoles can also be used as aspacer for nanofiber formation. [34] It should be noted that as the van der Waals forces bring the molecules together,o ther possible interactions may also occur betweent he self-assembled molecules. For example, p-p stacking may occur between benzene rings in the BTPE system,a nd the hydrophobic effect of the alkyl chains may contribute to the self-assembly of AIEgens with alkyl spacer chains.…”

Molecular Design, Circularly Polarized Luminescence, and Helical Self‐Assembly of Chiral Aggregation‐Induced Emission Molecules

“…[35,36] To expand the system,t he thiourea-linked chiral silole derivative 4 was synthesized by incorporatingc hiral phenylethanamine moieties onto the tetraphenylsilole unit. [37] Consideringt hat some achiral p-conjugated molecules can form helical assemblies through asymmetric packing of achiral building blocks, [38][39][40] we also prepared an achiral silole compound, hexaphenylsilole (HPS, 5)f or comparison. [41]…”

Synthesis of Amphiphilic Hyperbranched AIE‐active Fluorescent Organic Nanoparticles and Their Application in Biological Application

“…On the other hand, Zhang et al [36,37] have developed a number of covalent strategies for fabrication of AIE dyes containeing amphiphilic FONs through reversible addition-fragmentation chain-transfer (RAFT) polymerization and cross-linking. [38][39][40][41][42][43][44][45][46] However, most of these strategies still have some shortcoming. For example, most of commercially available amphiphilic compounds are expensive, and the obtained nanoprobes are often not stable when the concentration is lower than the critical micelle concentration (CMC).…”