Double-stranded cycles: toward C84's belt region.

Area of Science:

• Organic Chemistry
• Supramolecular Chemistry
• Materials Science

Background:

• Investigating the reactivity of complex hydrocarbon structures is crucial for developing novel materials.
• Cycle 1, a double-stranded hydrocarbon with ether bridges, presents a unique carbon skeleton resembling a C84 fullerene belt region.
• This structure suggests potential as a precursor for sought-after fully aromatic fullerene derivatives.

Purpose of the Study:

• To investigate the reactivity of the double-stranded hydrocarbon cycle (1) with iodotrimethylsilane (TMSI).
• To elucidate the reaction mechanism, including iodination, reduction, and potential H/D exchange.
• To explore the potential of cycle 1 as a fullerene precursor.

Main Methods:

• Reaction of cycle 1 with iodotrimethylsilane (TMSI) under varying conditions (dry, wet with H2O, and D2O).
• Structural elucidation of the hydrogenated product (5a) using single-crystal X-ray analysis.
• Mechanistic studies employing detailed Nuclear Magnetic Resonance (NMR) correlation spectroscopy and Density Functional Theory (DFT) computations.

Main Results:

• Cycle 1 undergoes a cascade of iodination and reduction reactions upon exposure to TMSI, yielding the hydrogenated cycle 5a.
• The structure of the hydrogenated cycle 5a was confirmed by X-ray crystallography.
• Detailed NMR and DFT studies revealed mechanistic insights, including an unexpected selective H/D exchange at the naphthalenic moieties under wet conditions.

Conclusions:

• The study clarifies the complex reaction pathway of cycle 1 with TMSI, demonstrating its transformation into a hydrogenated derivative.
• The findings provide valuable mechanistic understanding of fullerene precursor reactivity and H/D exchange processes.
• This research contributes to the synthetic strategies for novel fullerene derivatives and related carbon materials.