A dicationic distibine stabilized by intramolecular π-π interaction and second-sphere coordination.

Area of Science:

• Organometallic Chemistry
• Coordination Chemistry
• Antimony Chemistry

Background:

• Pincer ligands are versatile scaffolds in coordination chemistry.
• Antimony compounds are increasingly explored for unique electronic properties and reactivity.
• Understanding redox behavior of low-valent main group elements is crucial.

Purpose of the Study:

• To synthesize and characterize a new pincer ligand featuring an antimony(I) center.
• To investigate the structural and electronic properties of its oxidized dicationic form.
• To explore the redox reactivity of the antimony centers in the dication.

Main Methods:

• Synthesis of the pincer ligand (1).
• Single electron oxidation to form the dicationic distibine (2).
• X-ray crystallography and computational studies (e.g., DFT).
• Reactions with disulfide and cobalt carbonyls to probe redox behavior.

Main Results:

• Successful synthesis of a novel Sb(I) pincer ligand (1).
• Characterization of the dicationic distibine (2) revealing stabilization via π-π interactions and second-sphere coordination.
• Demonstration of dual redox reactivity in reactions with a disulfide and Co2(CO)8, involving Sb-Sb bond oxidation and Sb(II) center reduction.

Conclusions:

• The new pincer ligand provides a platform for exploring antimony's redox chemistry.
• Intramolecular interactions play a significant role in stabilizing the oxidized antimony species.
• The observed dual redox reactivity highlights the potential of this system in diverse chemical transformations.