Abstract Improving luminous efficiency and mechanoresponsive luminescent (MRL) performance are significant issues in developing functional fluorescent materials. Herein, three push-pull typed carbazole derivatives with similar building blocks but differing in 2-vinylphenylmalononitrile acceptor numbers form mono- (m-VPMCz) to bis- (b-VPMCz) and tetra- (t-VPMCz) were designed and synthesized. Their luminescent properties in solution and aggregate states, as well as MRL performance were investigated. It was demonstrated that t-VPMCz with the highest acceptor-density and a highly twisted configuration achieved the highest luminescent efficiency in both solution and aggregation. b-VPMCz adopting a moderately twisted structure with two acceptor units exhibited the most remarkable MRL performance accompanied with the most distinct phase transition upon grinding. Our results suggest that rational control over the acceptor-density on push-pull typed molecules would be a promising way for realizing advanced functional fluorescent materials.

中文翻译：

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用于提高发光效率和机械响应发光的推拉型咔唑衍生物的受体密度工程

摘要 提高发光效率和机械响应发光（MRL）性能是开发功能性荧光材料的重要课题。在此，设计并合成了三种具有相似结构单元但 2-乙烯基苯基丙二腈受体数不同的推拉型咔唑衍生物，形成单-(m-VPMCz) 到双-(b-VPMCz) 和四-(t-VPMCz)。研究了它们在溶液和聚集状态下的发光特性以及 MRL 性能。结果表明，具有最高受体密度和高度扭曲构型的 t-VPMCz 在溶液和聚集中都实现了最高的发光效率。b-VPMCz 采用具有两个受体单元的适度扭曲结构，表现出最显着的 MRL 性能，并伴随着最明显的研磨相变。我们的结果表明，合理控制推拉型分子的受体密度将是实现先​​进功能荧光材料的一种有前途的方法。