Smallest acyclic tricationic molecule containing a Bis(phosphine)-stabilized low-valent triantimony-based Unit.

Area of Science:

• Inorganic Chemistry
• Materials Science

Background:

• Multiply charged cationic element-element bonded species are typically observed as dimers or cyclic oligomers in condensed phases.
• The smallest acyclic version of such a species, a trinuclear unit with a charge greater than monocationic, has not been previously isolated or characterized.

Purpose of the Study:

• To synthesize and characterize a novel, low-valent, acyclic, multiply charged cationic antimony species.
• To investigate the structural, electronic, and reactive properties of this unique compound.

Main Methods:

• Synthesis of a bis(phosphine) supported triantimony tricationic compound.
• Structural elucidation using single crystal X-ray diffraction analysis.
• Electronic structure analysis to understand bonding and electron distribution.

Main Results:

• Isolation and characterization of a W-shaped, low-valent triantimony tricationic unit with a three-center four-electron sigma bond.
• Identification of a unique counter trianion, [Sb(O)2(OTf)4]3-, with reactive polar Sb-O bonds.
• Demonstration of the compound's thermal instability and diverse reactivity, leading to novel antimony compounds.

Conclusions:

• The successful synthesis and characterization of the smallest acyclic multiply charged cationic antimony species represent a significant advancement in the field.
• The compound's unique structure and reactive fragments enable the isolation of new antimony derivatives.
• The reactivity of this fleeting species was leveraged to form a novel low-valent antimony-cobalt carbonyl cluster.