A Borane Platinum Complex Undergoing Reversible Hydride Migration in Solution

Area of Science:

• Organometallic Chemistry
• Coordination Chemistry
• Materials Science

Background:

• Platinum complexes are crucial in catalysis and materials science.
• Understanding metal-ligand interactions is key to designing new functional materials.
• The reactivity of platinum(II) complexes with boron-containing ligands is an area of active research.

Purpose of the Study:

• To synthesize and characterize novel platinum complexes with 2-mercapto-benzimidazole ligands.
• To investigate the structural features and reactivity of these complexes, particularly the Pt-B interaction.
• To explore the potential for Pt-H bond activation and subsequent hydrolysis.

Main Methods:

• Synthesis of platinum complexes using [Pt(κ²-C,N-ppy)(dmso)Cl] and Na[H₂B(mb)₂].
• Characterization using single-crystal X-ray diffraction (SC-XRD) and multinuclear NMR spectroscopy.
• Investigation of solution-state equilibria and hydrolysis reactions.

Main Results:

• A novel hexacoordinated platinum(II) complex, {[(κ³-S,B,S-HB(mb)₂]Pt(κ²-C,N-ppy)H} (2), was synthesized, featuring a strong reverse-dative Pt → B σ interaction.
• Complex 2 undergoes reversible Pt-H bond activation in solution, forming a tetracoordinate complex, {[(κ²-S,S-H₂B(mb)₂]Pt(κ²-C,N-ppy)} (3).
• Hydrolysis of complex 2/3 leads to the formation of a dimeric half-lantern platinum(II,II) complex, [{Pt(κ²-C,N-ppy)(μ₂-κ²-N,S-mb)}₂] (4).

Conclusions:

• The study demonstrates the successful synthesis and characterization of unique platinum complexes with a Pt-B interaction.
• Reversible Pt-H bond activation and subsequent hydrolysis pathways were elucidated.
• The findings contribute to the understanding of platinum complex reactivity and the development of novel platinum-based materials.