A Thermally Populated Germylene-Based Donor-Acceptor Diradical.

Area of Science:

• Organometallic Chemistry
• Materials Science
• Photochemistry

Background:

• Germylene chemistry is crucial for developing novel materials with unique electronic properties.
• Donor-acceptor molecules offer tunable electronic behavior for advanced applications.
• Controlling spin states in molecules is key for quantum computing and spintronics.

Purpose of the Study:

• To synthesize a novel germylene-based donor-acceptor molecule.
• To investigate the thermal excitation to a triplet state via Lewis acid coordination.
• To explore the formation of thermally populated open-shell species in heavier main group elements.

Main Methods:

• Synthesis of a germylene-based donor-acceptor molecule.
• Coordination with Boron(tris(pentafluorophenyl)) (BCF) as a Lewis acid.
• Characterization using single crystal X-ray diffraction, EPR spectroscopy, and SQUID measurements.
• Computational analysis using Density Functional Theory (DFT) calculations.

Main Results:

• The singlet-triplet energy gap was significantly reduced from -18.8 to -7.2 kcal/mol upon BCF coordination.
• Intramolecular single electron transfer occurred upon heating, forming a radical ion pair.
• The resulting species exhibited diradical character, indicating an open-shell nature.

Conclusions:

• Coordination with Lewis acids effectively modulates the electronic properties of germylene-based donor-acceptor molecules.
• This study presents a viable approach for generating thermally accessible open-shell radical species from heavier main group elements.
• The findings open new avenues for designing molecules with tunable spin states for advanced material applications.