Xiao Yi-Hong, Ma Zhi-Zhou, Yang Xue-Xian, Li Dong-Sheng, Gu Zhi-Gang, Zhang Jian
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, 350002 Fuzhou, People's Republic of China.
College of Environmental and Biological Engineering, Fujian Provincial Key Laboratory of Ecology-Toxicological Effects & Control for Emerging Contaminants, Key Laboratory of Ecological Environment and Information Atlas (Putian University) Fujian Provincial University, Putian University, Putian 351100, People's Republic of China.
ACS Nano. 2023 Oct 10;17(19):19136-19143. doi: 10.1021/acsnano.3c05265. Epub 2023 Sep 22.
Combining the features of the host-guest system and chirality is an efficient strategy to achieve circularly polarized luminescence (CPL). Herein, well-defined chiral carbon nanodot (chirCND) arrays were confined-synthesized by low-temperature calcination of a chiral amino acid loaded metal-organic framework (MOF) to induce high CPL. An achiral porous pyrene-based MOF NU-1000 thin film as the host template was prepared by a liquid-phase epitaxial layer-by-layer fashion, and chiral amino acids as the carbon sources could be confined in the porous MOF and carbonized to homogeneous and ultrasmall chirCND arrays, resulting in a chirCNDs@NU-1000 thin film (l-CNDs@NU-1000; = l-cysteine (cys), l-serine, l-histidine, l-glutamic acid, and l-pyroglutamic acid). The results show the pristine chirCNDs by directly carbonizing chiral amino acids hardly endow them with a CPL property. By contrast, benefiting from the arrayed confinement and coordination interaction between chirCNDs and NU-1000, the chirality transfer on the excited state of chirCNDs@NU-1000 is enabled, leading to strong CPL performance (a high luminescence dissymmetry factor of l-CNDs@NU-1000 thin film reached 1.74 × 10). This study of chirCNDs encapsulated in fluorescent MOF thin films provides a strategy for developing uniform chiral carbon nanoarrays and offers chiral host-guest thin-film materials for optical applications.
结合主客体系统和手性的特征是实现圆偏振发光（CPL）的有效策略。在此，通过对负载手性氨基酸的金属有机框架（MOF）进行低温煅烧，受限合成了定义明确的手性碳纳米点（chirCND）阵列，以诱导高CPL。通过液相外延逐层方式制备了一种非手性的基于芘的多孔MOF NU-1000薄膜作为主体模板，手性氨基酸作为碳源可被限制在多孔MOF中并碳化，形成均匀且超小的chirCND阵列，从而得到chirCNDs@NU-1000薄膜（l-CNDs@NU-1000；l = l-半胱氨酸（cys）、l-丝氨酸、l-组氨酸、l-谷氨酸和l-焦谷氨酸）。结果表明，直接碳化手性氨基酸得到的原始chirCNDs几乎不具备CPL特性。相比之下，得益于chirCNDs与NU-1000之间的阵列限制和配位相互作用，chirCNDs@NU-1000激发态上的手性转移得以实现，从而产生强CPL性能（l-CNDs@NU-1000薄膜的高发光不对称因子高达1.74×10）。这项关于包裹在荧光MOF薄膜中的chirCNDs的研究为开发均匀的手性碳纳米阵列提供了一种策略，并为光学应用提供了手性主客体薄膜材料。
