Bicyclo[1.1.0]tetragermane-2,4-diide Diradicaloid

Area of Science:

• Organometallic Chemistry
• Inorganic Chemistry
• Materials Science

Background:

• Germanium clusters are underexplored compared to silicon analogues.
• Anionic dicarbene ligands offer unique coordination environments for main group elements.
• Exploring novel bonding motifs in low-valent germanium compounds is crucial.

Purpose of the Study:

• To synthesize and characterize a novel bicyclo[1.1.0]tetragermane-2,4-diide.
• To investigate the electronic structure and bonding of the Ge4 core.
• To explore the reactivity of the tetragermane compound with radical and metal-containing reagents.

Main Methods:

• Synthesis of a Ge4 core compound using GeCl4 and an alkyne-functionalized amidine.
• KC8 reduction for the formation of the tetragermane-2,4-diide.
• Density Functional Theory (DFT) and Complete Active Space Self-Consistent Field (CASSCF) calculations for electronic structure analysis.
• Reactions with TEMPO and Fe2(CO)9 to probe reactivity.

Main Results:

• Successful synthesis of the bicyclo[1.1.0]tetragermane-2,4-diide, [(ADC)Ge2]2, featuring a Ge4 core.
• DFT and CASSCF calculations indicate a singlet ground state with a modest diradical character.
• The compound undergoes Ge-Ge bond cleavage upon reaction with TEMPO and Fe2(CO)9.

Conclusions:

• The study reports the first synthesis of a bicyclo[1.1.0]tetragermane-2,4-diide.
• The electronic structure reveals interesting bonding characteristics of the Ge4 core.
• The reactivity studies demonstrate the potential of this novel germanium compound in further synthetic transformations.