Ambient Temperature Isolation of a Monatomic Boron(0) Complex.

Area of Science:

• Inorganic Chemistry
• Organometallic Chemistry
• Main Group Chemistry

Background:

• Neutral low-coordinate boron species are rare and challenging to synthesize and isolate.
• Understanding the bonding and reactivity of such species is crucial for advancing main group chemistry.

Purpose of the Study:

• To synthesize and characterize the first bottleable neutral Group 13 atom complex.
• To explore the reactivity of this complex through reduction and oxidation reactions.
• To investigate the electronic structure and bonding of the synthesized boron complex.

Main Methods:

• Synthesis of a neutral two-coordinate boron complex stabilized by cyclic (alkyl)(amino)carbene (CAAC) ligands.
• Characterization using spectroscopic methods and single-crystal X-ray diffraction.
• Exploration of reactivity via reduction to a boride anion and oxidation to a boron(I) complex.
• Computational analysis using Density Functional Theory (DFT) to understand bonding.

Main Results:

• Isolation and full characterization of the first bottleable neutral boron(0) complex, L2B0.
• Successful reduction to a stable diamagnetic boride anion.
• Trapping of a transient cationic borylene intermediate to form a stable boron(I) complex.
• DFT calculations confirmed strong multiple bonding in the boron(0) complex.

Conclusions:

• The study presents the first isolable neutral two-coordinate boron(0) complex, stabilized by CAAC ligands.
• The boron(0) complex exhibits rich redox chemistry, leading to stable boride and boron(I) species.
• The findings provide fundamental insights into the nature of bonding in low-coordinate boron compounds.