Metallacyclobuta-2,3-dienes as organometallic analogs of the smallest cyclic allene – classical metallacyles or unusual transition metal biradcals?

• Applicant: Professor Dr. Torsten Beweries
• Subject Area: Inorganic Molecular Chemistry - Synthesis and Characterisation
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 452714985

The project aims at the investigation of synthesis and reactivity of highly unusual metallacyclobuta-2,3-dienes. Based on previous work on an ansa-titanocene system also other group 4 metals, metallocene fragments and allene subtitution patterns will be investigated. One of the main goals is to thoroughly characterise metallacyclobuta-2,3-dienes theoretically and spectroscopically. Previous studies have shown a distinct and unusual biradical character of complex 3. This raises the question whether the reactivity of such compounds is dominated by this phenomenon or whether reactivity patterns found for classical metallacycles occur. The findings of this project will have impact for organometallic chemistry and theoretical inorganic chemistry.The project is composed of the following work packages:- Synthesis of suitable allene precursors (AP1)- Synthesis of new metallacyclobuta-2,3-dienes (AP2)- Spectroscopic and theoretical characterisation of metallacyclobuta-2,3-dienes (AP3)- Reactivity of metallacyclobuta-2,3-dienes (AP4)

• DFG Programme: Research Grants