A cooperative pathway for water activation using a bimetallic Pt⁰-Cu^I system

Area of Science:

• Organometallic chemistry
• Coordination chemistry
• Catalysis

Background:

• Platinum(0) complexes are versatile precursors in organometallic synthesis.
• Copper(I) complexes can act as Lewis acids and co-catalysts.
• Water activation is a key step in many catalytic processes.

Purpose of the Study:

• To investigate the reaction between a platinum(0) complex and a copper(I) salt in the presence of water.
• To characterize the resulting platinum(II) hydride complex and elucidate the reaction mechanism.
• To study the reactivity of the platinum(II) hydride complex with pyridine.

Main Methods:

• X-ray crystallography for structural determination of platinum complexes.
• Low-temperature NMR spectroscopy (¹H and ³¹P) to monitor reaction pathways.
• Spectroscopic analysis (NMR) and X-ray crystallography to characterize products.

Main Results:

• Formation of a platinum(II) hydride complex ([PtH(CH₃CN)(PᵗBu₃)₂]PF₆) and a copper(I) hydroxide species via water activation.
• Identification of a cooperative pathway involving a Pt⁰-Cuᴵ dative bond as the most probable mechanism.
• Synthesis and structural characterization of a cyclometalated platinum(II) complex ([Pt(κ²ₚᴄ-PᵗBu₂CMe₂CH₂)(py)₂]) through intramolecular C-H activation.

Conclusions:

• The platinum(0)/copper(I) system effectively activates water, yielding a stable platinum(II) hydride.
• A cooperative mechanism involving a Pt-Cu dative bond is crucial for water activation.
• The platinum(II) hydride complex exhibits reactivity towards pyridine, leading to cyclometalation.