Fabrication of single-chain nanoparticles through the dimerization of pendant anthracene groups via photochemical upconversion

Abstract

We report on the use of visible light as the driving force for the intramolecular dimerization of pendant anthracene groups on a methacrylic polymer to induce the formation of single-chain nanoparticles (SCNPs). Using a 532 nm green laser light source and platinum octaethylporphyrin as a sensitizer, we first demonstrated the use of TTA-UC to dimerize monomeric anthracene, and subsequently applied this concept to dilute poly((methyl methacrylate)-stat-(anthracenyl methacrylate)) samples. A combination of triple-detection size-exclusion chromatography, atomic force microscopy, and UV-visible spectroscopy confirmed the formation of the SCNPs. This report pioneers the use of TTA-UC to drive photochemical reactions in polymeric systems, and showcases the potential for TTA-UC in the development of nanoobjects.

Supramolecular Single-Chain Polymeric Nanoparticles

“…This was achieved via the use of dynamic covalent cross-links, using disulfide, hydrazone, enamine, Diels-Alder, or reversible photodimerization chemistry. [61][62][63][64][65][66][67][68][69][70][71][72] Although the bonds formed using this type of chemistry are, in principle, covalent, they can be broken, reshuffled, and reformed under specific conditions.…”

Advances in the Phototriggered Synthesis of Single-Chain Polymer Nanoparticles

“…Subsequently, the strategy of intrachain photodimerization of pendant anthracene units was adopted by Zhao et al to construct amphiphilic, Janus twin SCNPs [28] and biohybrid vesicles by coassembly of proteins and tadpole-shaped SCNPs [29], and by Temel and coworkers [30] to develop SCNPs as carbon nanotube catchers. On the other hand, Simon and coworkers [31] pioneered the use of visible light (λ = 532 nm) in the presence of a sensitizer (platinum octaethylporphyrin) as the driving force for SCNP formation through dimerization of pendant anthracene groups via photochemical upconversion (see Figure 4). Conventional anthracene dimerization was selected by Barner-Kowollik et al [32] for photoactivated SCNP formation under UV irradiation at λ = 330 nm, before the photoactivated ligation of the formed SCNP with a second polymer chain using blue light (λ = 455 nm).…”

“…Several applications have been suggested for the different SCNPs prepared from photocross-linking, including (i) imprintable nano-materials with high binding capacities and selectivities [21]; (ii) tunable nanoreactors for the synthesis of gold nanoparticles (AuNPs) [23,24]; (iii) CO 2 -capture nanomaterials [24]; (iv) advanced Janus surfactants [28]; (v) biohybrid vesicles as protein carriers [29]; (vi) carbon nanotube catchers [30]; (vii) photoresponsive liquid crystalline nanomaterials [25,34]; (viii) new, fluorescent, soft nanomaterials [26,27,28,29,30,31,32,36,37,38,40,42,47,48,49,50,53]; (ix) adaptative, dynamic nano-particles [43,44,45]; (x) totally deuterated nanomaterials for the investigation of the structures and dynamics of all-polymer nanocomposites [41]; (xi) photodegradable nanomaterials [58]; and (xii) nanoreactors for the syntheses of polymers [59].…”

“…Schematic illustration of the synthesis of SCNPs through photochemical upconversion (also referred to as triplet–triplet annihilation upconversion) via intrachain dimerization of pendant anthracene groups under visible light irradiation (λ = 532 nm) in the presence of platinum octaethylporphyrin as a sensitizer. Reprinted from [31] with permission.…”

Anti‐Stokes‐Belastungsanzeige: Mechanochemische Aktivierung der Triplett‐Triplett‐Annihilierung‐Photonen‐Hochkonversion

“…[36,37] PtOEP besitzt aufgrund der hohen Spin-Bahn-Kopplung,die durch das schwere Pt-Atom mit einer S 0 !T 1 Tr iplettenergie von 1.921 eV induziert wird, eine gute Interkombinationseffizienz. [36,37] PtOEP besitzt aufgrund der hohen Spin-Bahn-Kopplung,die durch das schwere Pt-Atom mit einer S 0 !T 1 Tr iplettenergie von 1.921 eV induziert wird, eine gute Interkombinationseffizienz.…”