Binuclear Aromatic C-H Bond Activation at a Dirhenium Site

Area of Science:

• Organometallic Chemistry
• Inorganic Chemistry
• Catalysis

Background:

• Electronically unsaturated dirhenium complexes are key intermediates in various catalytic processes.
• Aromatic C-H activation is a fundamental transformation in synthetic chemistry, enabling functionalization of inert C-H bonds.
• Understanding the reactivity of dirhenium complexes is crucial for developing novel catalytic systems.

Purpose of the Study:

• To investigate the aromatic C-H activation capabilities of the dirhenium complex [Re2(CO)8(μ-H)(μ-Ph)] (1).
• To synthesize and characterize new dirhenium complexes resulting from C-H activation reactions.
• To elucidate the reaction mechanism using computational methods.

Main Methods:

• Reaction of [Re2(CO)8(μ-H)(μ-Ph)] (1) with N,N-diethylaniline, naphthalene, and [D6]benzene.
• Characterization of the resulting products using spectroscopic techniques (NMR, Mass Spectrometry, X-ray crystallography).
• Density Functional Theory (DFT) computational analyses to investigate the reaction mechanism.

Main Results:

• The dirhenium complex (1) successfully underwent aromatic C-H activation with N,N-diethylaniline, naphthalene, and [D6]benzene.
• Good yields of the new dirhenium complexes [Re2(CO)8(μ-H)(μ-η(1)-NEt2C6H4)] (2), [Re2(CO)8(μ-H)(μ-η(2)-1,2-C10H7)] (3), and [D6]-1 were obtained.
• DFT calculations confirmed a binuclear C-H bond-activation process.

Conclusions:

• The electronically unsaturated dirhenium complex (1) is a potent reagent for aromatic C-H activation.
• The study provides mechanistic insights into the binuclear C-H bond-activation pathway.
• This work expands the scope of reactivity for dirhenium complexes in C-H functionalization.