Structure and ultrafast dynamics of tri-nuclear Ag-/Tl-Pt₂POP₄ complexes in solution

Area of Science:

• Inorganic chemistry
• Materials science
• Physical chemistry

Background:

• Ion assembly in solution influences nanomaterials and inorganic synthesis.
• The structural and electronic properties of trinuclear silver and thallium complexes of the diplatinum ion (PtPOP) are not well understood.
• Metal-metal bond formation is key to molecular and material assembly.

Purpose of the Study:

• Investigate the fundamental processes of ion assembly in solution.
• Elucidate the dynamics of silver-PtPOP and thallium-PtPOP complexes.
• Develop an electronic structure model for metal-metal bonding.

Main Methods:

• Time-resolved X-ray solution scattering (TR-XSS) was employed.
• Model-independent analysis of observed dynamics was performed.
• Time-resolved structural refinements with <100 fs resolution were incorporated.

Main Results:

• Photoexcitation caused Pt atoms to contract ~0.25 Å in both Ag-PtPOP and Tl-PtPOP.
• Ag-PtPOP showed an ultrafast Ag-Pt bond expansion (~0.2 Å).
• Tl-PtPOP exhibited a Tl-Pt bond contraction (~0.3 Å).
• Coherent oscillations along metal-Pt coordinates were observed in both complexes.

Conclusions:

• The study provides insights into the excited-state dynamics of metal-metal bonds.
• An electronic structure model for ground and excited states of Ag-PtPOP and Tl-PtPOP was proposed.
• These findings advance understanding of molecular assembly in solution.