Frisch Hendrik, Menzel Jan P, Bloesser Fabian R, Marschner David E, Mundsinger Kai, Barner-Kowollik Christopher
School of Chemistry, Physics and Mechanical Engineering , Queensland University of Technology , 2 George Street , Brisbane , Queensland 4000 , Australia.
Macromolecular Architectures, Institut für Technische Chemie und Polymerchemie , Karlsruhe Institute of Technology , Engesserstrasse 18 , 76131 Karlsruhe , Germany.
J Am Chem Soc. 2018 Aug 1;140(30):9551-9557. doi: 10.1021/jacs.8b04531. Epub 2018 Jul 13.
Emulating nature's protein paradigm, single-chain nanoparticles (SCNP) are an emerging class of nanomaterials. Synthetic access to SCNPs is limited by ultralow concentrations, demanding reaction conditions, and complex isolation procedures after single-chain collapse. Herein, we exploit the visible light photodimerization of styrylpyrene units as chain folding mechanism. Critically, their positioning along the polymer chain creates a confined environment, increasing the photocycloaddition quantum yields dramatically, enabling single-chain folding at unrivaled high concentrations without subsequent purification. Importantly, the enhanced photoreactivity allows for single-chain folding at λ = 445 nm LED-irradiation within minutes as well as via ambient light, enabling an unprecedented folding system. The herein demonstrated enhancement of quantum yields by steric confinement serves as a blueprint for all photochemical ligation systems.
模仿自然界的蛋白质范式，单链纳米颗粒（SCNP）是一类新兴的纳米材料。合成SCNP受到超低浓度、苛刻的反应条件以及单链折叠后复杂的分离程序的限制。在此，我们利用苯乙烯基芘单元的可见光光二聚作用作为链折叠机制。关键的是，它们沿聚合物链的定位创造了一个受限环境，极大地提高了光环加成量子产率，能够在无与伦比的高浓度下进行单链折叠而无需后续纯化。重要的是，增强的光反应性允许在λ = 445 nm的LED照射下几分钟内以及通过环境光进行单链折叠，从而实现了前所未有的折叠系统。本文所展示的通过空间限制提高量子产率为所有光化学连接系统提供了一个蓝图。
