Homo- and heteroleptic beryllium organyls: structure, properties and application in Grignard-analogue reactions and for the synthesis of low-valent compounds

• Applicant: Dr. Magnus Richard Buchner
• Subject Area: Inorganic Molecular Chemistry - Synthesis and Characterisation
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 563432983

In order to obtain a comprehensive understanding of the structure, stability, properties and reactivity of homo- and heteroleptic beryllium alkyls and aryls and to verify the knowledge postulated in textbooks, a broad library of these compounds is to be built up, which also includes corresponding beryllium hydrides. The obtained compounds will then be reacted in Grignard analogue reactions to obtain a comparison with related magnesium, lithium, aluminium and boron compounds. In addition, the insights gained into the reactivity and the synthesised compounds will be used for the preparation of low-valent beryllium compounds and Be-Be multiple bonds. The project is divided into two work packages entitled ‘Beryllium alkyls and aryls’ and ‘Beryllocenes’. From the work package ‘Beryllium alkyls and aryls’ a coherent understanding of the structures and properties of beryllium organyls and hydrides will be obtained and the bonding conditions in these compounds will be analysed. This will allow for the first time an experimental verification of the postulated chemistry of these textbook compounds. By reacting the synthesised beryllium organyls with typical substrates for Grignard and cross-coupling reactions, a comparative and comprehensive understanding of typical organometallic and organoboronic synthesis reagents will be obtained on the one hand and special applications for synthesis problems will be explored on the other. Since it has already been shown that the reactivity of beryllium organyls lies between comparable compounds of lithium, magnesium, aluminium and boron, it is also expected that the compounds obtained will be synthetically relevant for special applications, especially in view of the expected good definition, solubility and stability in chlorinated solvents. For example, the introduction of functional groups on sterically strongly shielded carbon atoms or on poorly soluble substrates is conceivable. The second work package will provide a comprehensive understanding of the reactivity of beryllocenes. In view of the increased importance of beryllocenes in current low-valent main group chemistry, the development of the previously lacking understanding of the structure-property relationships of beryllocenes and their reactivity is highly relevant. In parallel, the reactivity of the new substance class of diberyllocenes will be comprehensively investigated. These results will then be utilised directly in the synthesis of novel low-valent beryllium compounds and complexes with Be—Be single, Be=Be double and Be≡Be triple bonds. These substances should exhibit previously unknown reactivities and would thus make a significant contribution to the currently heavily researched field of low-valent main group chemistry.

• DFG Programme: Research Grants