Fluorescent heteroditopic and redox-active sensors for sulfide and pH/Eh

硫化氢（H2S）是一种有毒的腐蚀性气体，既存在于自然界，也由化石燃料燃烧和垃圾填埋场人为产生。当溶解在水中时，H2S主要以阴离子形式存在，即硫化氢（HS）。这种阴离子带来了许多问题，包括污水基础设施的退化和金属废物容器的腐蚀-特别是用于储存核废料的容器。因此，感知和监测硫化氢水平具有重要的工业和公共意义。以前的硫化氢检测方法存在不可逆的缺点，因此不适合连续监测。因此，该项目的目标之一是开发能够连续可逆地监测硫化氢水平的荧光传感器。近年来，卤素键已被证明是一种识别阴离子的强大相互作用，并且对硫化氢具有理想的选择性，优于水中常见的其他阴离子，包括氯化物。异位受体-具有两个不同结合位点的受体，可同时识别带相反电荷的物种-由于其对带电物种的亲和力和选择性比其简单的单位类似物更强，最近也引起了人们的关注。该项目旨在建立在这些最新发展的基础上，通过将氢硫化物结合的卤素键基元和阳离子结合区域结合到荧光分子骨架中，从而可以感知水中常见的氢硫化物盐。卤素键异位氢硫化物盐在水中的识别是前所未有的，而在任何溶剂体系中对硫化物的选择性识别仍然很少见。因此，对这一领域的进一步探索将有助于更好地了解成功的氢硫化物识别系统的特征和要求。水源的酸度（pH）和还原潜力（Eh）对基础设施和工业也至关重要，因为它们对关键材料和组件的寿命和稳定性有相当大的影响。卤素键在pH或Eh化学传感器设计中的应用是前所未有的，因此该项目的另一个方面是寻求开发新型卤素键化学传感器，该传感器通过灵敏的光学方法响应pH值，并展示氧化还原活性，以监测Eh。总体而言，该项目旨在促进对水源特性的持续监测，以提高暴露于水的重要基础设施的耐久性和安全性。与放射性废物管理合作，该项目属于EPSRC合成超分子化学研究领域。

Hydrogen sulfide (H2S) is a poisonous and corrosive gas both found in nature and produced anthropogenically from fossil fuel combustion and landfill sites. When dissolved in water, H2S is primarily found in its anionic form, hydrosulfide (HS ). This anion presents numerous problems, including degradation of sewage infrastructure and corrosion to metal waste containers - notably those used to store nuclear waste. Sensing and monitoring hydrosulfide levels is therefore of significant industrial and public relevance. Previous hydrogen sulfide detection methods suffer from being irreversible, and therefore unsuitable for continuous monitoring purposes. Therefore, one of the aims of this project is to develop fluorescent sensors that are capable of monitoring hydrosulfide levels continuously and reversibly. In recent years, halogen bonding has been demonstrated to be a powerful interaction for the recognition of anionic species, and has shown a desirable selectivity for hydrosulfide over other anions commonly found in water, including chloride. Heteroditopic receptors - receptors possessing two distinct binding sites for the simultaneous recognition of oppositely charged species - have also latterly garnered attention due to their enhanced affinity and selectivity towards charged species relative to their simpler, monotopic analogues. This project seeks to build on these recent developments, by incorporating both a hydrosulfide-binding halogen bonding motif, and also a cation-binding region, into a fluorescent molecular backbone, allowing for the sensing of hydrosulfide salts commonly found in water. Halogen bonding heteroditopic hydrosulfide salt recognition in water is unprecedented, and indeed selective recognition of sulfide in any solvent system remains rare. Therefore, further exploration of this area will lead to a better understanding of the features and requirements of successful hydrosulfide recognition systems. The acidity (pH) and reducing potential (Eh) of water sources is also of critical relevance to infrastructure and industry, due to their considerable impacts on the longevity and stability of crucial materials and components. The application of halogen bonding in pH or Eh chemosensor design is unprecedented, and therefore another aspect of this project is to seek to develop novel halogen bonding chemosensors which respond to pH via sensitive optical methodologies and also demonstrate redox activity for the monitoring of Eh. Overall, this project seeks to facilitate the continuous monitoring of the properties of water sources to improve the durability and safety of important infrastructure exposed to water. Working in collaboration with Radioactive Waste Management, this project falls within the synthetic supramolecular chemistry EPSRC research area.