Bis(imino)carbazolate: A Master Key for Barium Chemistry.

Area of Science:

• Organometallic Chemistry
• Inorganic Synthesis
• Barium Chemistry

Background:

• Barium's complex synthetic chemistry presents challenges.
• Limited availability of stable, well-defined barium complexes hinders research.
• Novel ligands are crucial for accessing new barium species.

Purpose of the Study:

• To develop a versatile proligand for barium complex synthesis.
• To access rare and previously unknown solution-stable heteroleptic barium complexes.
• To characterize novel barium compounds, including fluoride, stannylide, silanylide, amide, and iodide.

Main Methods:

• Synthesis of a bis(imino)carbazole-based proligand.
• Preparation of heteroleptic barium complexes.
• Structural characterization using X-ray diffraction and other spectroscopic methods.
• Density Functional Theory (DFT) analysis of bonding.

Main Results:

• Successful synthesis of a readily available bis(imino)carbazole proligand.
• Preparation of the first molecular barium fluoride and barium stannylide with an unsupported Ba-Sn bond.
• Isolation and characterization of stable barium amide, iodide, and silanylide species.
• DFT analysis reveals predominantly ionic Ba-tetrelide bonding with minor covalent character.

Conclusions:

• The bis(imino)carbazole ligand provides a facile entry into barium chemistry.
• This work expands the scope of known molecular barium compounds.
• The synthesized barium amide serves as a stable precatalyst for hydrophosphination.