Dinuclear Copper(I) Complexes Featuring Metal-Metal Interactions and a μ₂-Bridging Phosphane With Additional Olefinic...

Area of Science:

• Coordination Chemistry
• Organometallic Chemistry

Background:

• The phosphane ligand Ptrop3 features a rigid dibenzo[a,d]cyclohepten-5-yl unit with an olefinic binding site.
• In mononuclear copper(I) complexes, Ptrop3 acts as a bulky ligand with weak interactions to the olefinic units.

Purpose of the Study:

• To investigate the coordination behavior of Ptrop3 in mononuclear and dinuclear copper complexes.
• To explore the influence of dinuclear copper complex formation on the interaction between the copper core and the Ptrop3 ligand's olefinic sites.

Main Methods:

• Synthesis and characterization of mononuclear [Cu(Ptrop3)X] and dinuclear [Cu2(μ2-Ptrop3)(μ2-X)]+ complexes.
• Experimental investigations including X-ray crystallography (implied).
• Density Functional Theory (DFT) calculations.

Main Results:

• Mononuclear copper(I) complexes exhibit weak interactions between the copper center and the olefinic C=C bonds of Ptrop3.
• Dinuclear complexes with a bridging Ptrop3 ligand show significantly enhanced interactions between the Cu2 core and the olefins.
• The formation of dinuclear complexes from mononuclear precursors is both kinetically and thermodynamically favorable.

Conclusions:

• Ptrop3's coordination mode and interaction strength with copper are highly dependent on the nuclearity of the complex.
• Dinuclear copper complexes offer a platform for stronger metal-olefin interactions mediated by the Ptrop3 ligand.
• The study highlights the potential of Ptrop3 in designing copper complexes with tunable electronic properties.