Taming, Training and Combining Subvalent Main-Group Cations of Group 13 and 14

• Applicant: Professor Dr. Ingo Krossing
• Subject Area: Inorganic Molecular Chemistry - Synthesis and Characterisation
• Term: since 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 400773200

In this extension project, the final goal is to bridge the gap from the stage of collecting beautiful "butterflies" of the heavier Group 13 cations, i.e., compounds with unusual structural and bonding properties, to a system that, upon addition of defined and commercially available chelating phosphane ligands, generates functional molecules that, cooperatively as trans-bent dimers or alone as carbene-analogous monomers, can activate bonds. The positive charge stabilizes the univalent stage and facilitates reductive elimination. Hence, the proposal describes two typical catalytic cycles for resulting project-relevant processes like hydroboration: On the one hand, a mechanism basing on oxidative addition and reductive elimination, and an alternative, Lewis acidic mechanism based on the Lewis-acidic trivalent oxidation products formed after oxidative addition. Further, the chemistry of the Al(I) cations just opened will be extended in the project, access to aromatic complexes of group 14 dications (Si-Pb) will be opened, and the combination of group 13 and 14 cations into heterobimetallic cluster cations will be investigated. In particular, the group 14 dication aromatic complexes are virtually without precedent and successful access would entail rich follow-up chemistry, e.g., by reaction with more electron-rich donors and playing with the orbital energy of the nonbonding ns2 orbitals of the ligated dications. In the second part of the project, therefore, "butterflies" are again specifically sought for in new territory, which are then to be tamed and brought to function. Hence, the title of the project indicates our goals: „Taming, Training and Combining Subvalent Main-Group Cations of Group 13 and 14“

• DFG Programme: Research Grants