Ultrafast monitoring and synthetic control of electronic properties of a self-assembled coordination system as a multi-site luminescent probe for sensoric and imaging applications

目前的方法旨在开发具有多个位点的分子或离子识别的分子荧光探针的新策略。我们提出了一种新的多位点荧光探针设计概念，它可以实现多路或逻辑系统响应或传感器特征的控制和切换，远远超出传统分子探针所观察到的，需要在超快光谱和理论指导下进行先进的合成。目标化合物通过金属模板希夫碱反应以模块化的方式构建，包含两个选择性结合位点，构成中心水杨环-醛二胺发色团单元的组成部分。过渡金属结合（Zn2+, Cu+）增强了A位点的荧光，而占据B位点（Li+, Na+, K+）则调节了荧光性质。利用液体和固体界面的光电子发射光谱、连续探针瞬态吸收和荧光寿命成像来监测系统的响应，并利用密度泛函理论解释数据，为选择性合成改进提供指导。

The present approach aims at a novel strategy to develop molecular fluorescent probes with more than one site for molecular or ion recognition. We propose a novel design concept for a multi-site fluorescence probe that enables a multiplex or logic system response or the control and switching of sensor features, much beyond those observed in conventional molecular probes, requiring advanced synthesis guided by ultrafast spectroscopy and theory. The target compounds, constructed in a modular approach by metal-templated Schiff-base reactions, contain two selective binding sites, which constitute an integral part of a central salicyclidene-aldimine chromophore unit. Transition metal binding (Zn2+, Cu+) at site A enhances the fluorescence, while occupation of site B (Li+, Na+, K+) modulates the fluorescence properties. The system responses are monitored with photoelectron emission spectroscopy from liquid and solid interfaces, continuum probe transient absorption and fluorescence lifetime imaging and the data are interpreted employing density functional theory providing the guidelines for selective synthetic improvements.