Lewis Acid Decorated Hexacyanodiborane(6) Dianion

Area of Science:

• Boron chemistry
• Organometallic chemistry
• Supramolecular chemistry

Background:

• The [B2(CN)6]2− dianion offers potential for novel chemical structures.
• Weakly coordinating anions are crucial for stabilizing reactive cationic species.

Purpose of the Study:

• To synthesize and characterize novel diborane(6) dianions.
• To explore the synthetic utility of the [B2(CN)6]2− dianion.
• To investigate the stabilizing capabilities of these new dianions.

Main Methods:

• Synthesis of diborane(6) dianions decorated with B(C6F5)3 (BCF) groups and SiEt3+ moieties.
• Isolation of the dianion [B2{CNB(C6F5)3}6]2− (1) as potassium and tetrabutylammonium salts.
• Stabilization of carbocation [Ph3C]+ and oxonium acid [H(OEt2)2]+ using dianion 1.
• Reaction with HSiEt3 to yield the silylated neutral diborane(6) [B2{CNB(C6F5)3}4(CNSiEt3)2] (2).

Main Results:

• First examples of diborane(6) dianions functionalized with BCF groups and SiEt3+ moieties were successfully synthesized.
• The synthesized dianion [B2{CNB(C6F5)3}6]2− (1) proved effective in stabilizing reactive cationic species like [Ph3C]+ and [H(OEt2)2]+.
• Selective replacement of BCF groups by SiEt3+ substituents in compound 2 highlights the chemical versatility of the [B2(CN)6]2− core.

Conclusions:

• The [B2(CN)6]2− dianion is a versatile platform for creating novel diborane(6) compounds with tunable properties.
• The synthesized compounds exhibit unique electronic, coordinating, and steric characteristics.
• This work expands the scope of weakly coordinating anions and their applications in stabilizing reactive intermediates.