Dihydrogen and Ethylene Activation by a Sterically Distorted Distibene

Area of Science:

• Organometallic Chemistry
• Main Group Chemistry
• Chemical Synthesis

Background:

• Distibenes, compounds featuring an antimony-antimony double bond, are of interest due to their unique electronic properties.
• Steric hindrance can significantly influence the stability and reactivity of low-coordinate main group compounds.

Purpose of the Study:

• To synthesize and characterize a sterically distorted distibene.
• To investigate the reactivity of this distibene with fundamental feedstock chemicals like hydrogen and ethylene.
• To explore the role of transient intermediates in the observed reactivity.

Main Methods:

• Synthesis of the sterically distorted distibene ([4]2).
• Solid-state characterization using X-ray diffraction.
• Solution-state characterization using Nuclear Magnetic Resonance (NMR) spectroscopy.
• Reactivity studies with H2 and ethylene.

Main Results:

• A sterically distorted distibene ([4]2) with a long Sb=Sb bond was successfully synthesized.
• NMR data indicated the dimer ([4]2) is stable in solution, even at elevated temperatures.
• Evidence suggests reversible dissociation to a transient stibinidene ([4]) species, responsible for reactivity with H2 and ethylene, observable via NMR.

Conclusions:

• The synthesized distibene exhibits transition-metal-like reactivity.
• This reactivity is mediated by a transient stibinidene intermediate, formed via reversible dissociation of the distibene dimer.
• NMR spectroscopy is a powerful tool for observing transient species in solution.