英国牛津大学Aldridge, Simon报道了氟化钙分子络合物中亲核反应性的实现。相关研究成果发表在2024年5月14日出版的《自然—化学》。

氟化钙是所有含氟化学品的最终来源。目前的合成方法依赖于使用由天然萤石和硫酸产生的HF。长期以来，直接由CaF₂构建E–F键的方法一直因其高晶格能、低溶解度和氟离子亲核性受损而受挫。对Ca–F部分的反应性几乎没有基本的了解可用于指导方法的开发；含有Ca–F键的定义明确的分子种类极为罕见，现有的例子是强烈聚集的，没有证据表明亲核氟化物递送。

相比之下，研究表明，通过靶向[Ln（X）₂CaF]型阴离子系统，可以合成含有单个Ca–F键的单体氟化钙络合物，包括通过从现有的C–F键中提取氟化物的途径。对单核和双核系统的比较结构和光谱研究，使人们能够定义分子氟化钙形成E–F键的结构-活性关系。

附：英文原文

Title: Enabling nucleophilic reactivity in molecular calcium fluoride complexes

Author: Struijs, Job J. C., Ellwanger, Mathias A., Crumpton, Agamemnon E., Gouverneur, Vronique, Aldridge, Simon

Issue&Volume: 2024-05-14

Abstract: Calcium fluoride is the ultimate source of all fluorochemicals. Current synthetic approaches rely on the use of HF, generated from naturally occurring fluorspar and sulfuric acid. Methods for constructing E–F bonds directly from CaF2 have long been frustrated by its high lattice energy, low solubility and impaired fluoride ion nucleophilicity. Little fundamental understanding of the reactivity of Ca–F moieties is available to guide methodology development; well-defined molecular species containing Ca–F bonds are extremely rare, and existing examples are strongly aggregated and evidence no nucleophilic fluoride delivery. Here, by contrast, we show that by targeting anionic systems of the type [Ln(X)2CaF], monomeric calcium fluoride complexes containing single Ca–F bonds can be synthesized, including via routes involving fluoride abstraction from existing C–F bonds. Comparative structural and spectroscopic studies of mono- and dinuclear systems allow us to define structure–activity relationships for E–F bond formation from molecular calcium fluorides.

DOI: 10.1038/s41557-024-01524-x

Source: https://www.nature.com/articles/s41557-024-01524-x