This grant is in the Organic and Macromolecular Chemistry Program. In this study the influence of the addition of highly reactive lithium or alkali metal salts of organic hydrocarbon anions to a series of standard organomagnesium reagents will be investigated. As these chemical species equilibrate, a new negatively charged carbanion is formed that exhibits greatly enhanced chemical reactivity. This dynamic equilibrium can also be favorably altered by the addition of crown ethers or complexing agents the sequester the positively charged metal ions resulting in markedly different chemical bahavior. Specifically, the proposed research is concerned with preparations, structures, and reactions of new organometallic species of main-group metals. A major portion of the research will concern magnesiate ions. These negative organomagnesium ions will be synthesized from ordinary organic compounds in a number of ways compounds, including addition of coordinating agents, such as crown ethers and cryptands, or simple salts, such as alkali metal alkoxides and tetraalkylammonium halides. Structures and reactions of magnesiate species will be investigated. Magnesiate ions generally are considerably more reactive than conventional organomagnesium compounds and with some substrates furnish different products. Other organomagnesium species to be synthesized and studied structurally include organomagnesium cations (RMg+) and diorganomagnesium compounds (R2Mg) that are stabilized by coordinating groups such as crown ethers. A portion of the proposed work also will involve preparation of new organometallic species of other metals, particularly species formed from organoaluminum or organozinc compounds with crown ethers.
