Donor-Stabilized Fluorido Cations and New Tungsten-Based Weakly Coordinating Anions

供体稳定的氟阳离子和新型钨基弱配位阴离子

• 批准号: RGPIN-2022-03698
• 负责人: Gerken, Michael
• 金额: $ 4.52万
• 依托单位: University of Lethbridge
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=748460
• 关键词: Donor; Stabilized; Fluorido; Cations; New

The element fluorine is unique in the periodic table because it has the highest electronegativity and it is amongst the smallest in size. While it forms very stable C-F bonds, which are important in organofluorine chemistry, molecular inorganic fluorine compounds are characterized by their high reactivity. As a consequence, inorganic fluorine chemists utilize specialized synthetic methodologies, such as exclusion of moisture and maintaining samples at low temperature. Fluorine enables the synthesis of types of compounds that could not be made with other elements. Hence fluorine compounds have served as model compounds with unique reactivity profiles. Chemistry of the element fluorine has experienced a remarkable renaissance in the last decade, with spectacular discoveries and the outstanding utility of organofluorine compounds in the pharmaceutical and agrochemical industry. However, incorporation of fluorine almost always requires the use of reactive inorganic fluorinating agents. To ensure that the full range of fluorinated products is maintained and to improve safety, efficiency and selectivity, new fluorinating reagents are always needed. The current proposal focuses on inorganic fluorine chemistry and explores fundamental structural and reactivity questions, as well as potential applications of inorganic fluorides. The inorganic fluorine chemistry group in Lethbridge is one of the few groups in the world that can handle highly reactive fluorine chemicals and train students in this important field of chemistry. The proposal explores the preparation of fluorine-containing cations that are stabilized by donor molecules. Without the presence of these donor-molecules the cations would not form. The cations include main group (antimony, arsenic and sulfur) as well as transition metal (molybdenum, tungsten and rhenium) fluorides. These new cations exhibit interesting structures and reactivities that will allow their use as model compounds for high-coordinate geometries. Applications of salts of these cations will be explored as fluoride-ion acceptors, fluorination reagents and as pentafluorosulfanyl (-SF5) transfer agents. The second portion of the proposal targets new weakly coordinating anions, which are big anions where the negative charge is delocalized over a large volume. Weakly coordinating anions have already attracted vast attention in industry. This proposal targets a new class of such anions that could provide advantages to the currently used weakly coordinating anions. Applications of such anions range from lithium ion batteries to ionic liquids. Ionic liquids are important to further develop "green" chemistry since they are recyclable and do not have a vapour pressure and therefore will not cause atmospheric pollution.

氟元素在元素周期表中是独一无二的，因为它具有最高的电负性，并且它是最小的。虽然它形成非常稳定的C-F键，这在有机氟化学中很重要，但分子无机氟化合物的特征在于它们的高反应性。因此，无机氟化学家利用专门的合成方法，如排除水分和保持样品在低温下。氟可以合成其他元素无法合成的化合物。因此，氟化合物作为具有独特反应性的模型化合物。在过去的十年中，氟元素的化学经历了一次非凡的复兴，有机氟化合物在制药和农业化学工业中的惊人发现和杰出用途。然而，氟的掺入几乎总是需要使用反应性无机氟化剂。为了确保保持全系列的氟化产品并提高安全性、效率和选择性，始终需要新的氟化试剂。目前的建议集中在无机氟化学和探索基本的结构和反应性问题，以及无机氟化物的潜在应用。莱斯布里奇的无机氟化学小组是世界上少数几个能够处理高活性氟化学品并培养这一重要化学领域学生的小组之一。该提案探讨了由供体分子稳定的含氟阳离子的制备。没有这些供体分子的存在，阳离子就不会形成。阳离子包括主族（锑、砷和硫）以及过渡金属（钼、钨和铼）氟化物。这些新的阳离子表现出有趣的结构和反应性，将允许它们作为模型化合物的高坐标几何形状。这些阳离子的盐的应用将被探索作为氟离子受体，氟化试剂和作为五氟硫烷基（-SF 5）转移剂。该提案的第二部分针对新的弱配位阴离子，它们是负电荷在大体积上离域的大阴离子。弱配位阴离子在工业上已经引起了广泛的关注。该提议针对一类新的此类阴离子，其可以为目前使用的弱配位阴离子提供优势。这种阴离子的应用范围从锂离子电池到离子液体。离子液体对于进一步发展“绿色”化学是重要的，因为它们是可回收的并且不具有蒸气压，因此不会引起大气污染。