1,4-Diazacubane crystal structure rectified as piperazinium

Area of Science:

• Inorganic Chemistry
• Materials Science
• Computational Chemistry

Background:

• Azacubanes are theoretically stable nitrogen-containing analogues of cubane.
• The synthesis of 1,4-diazacubane was previously reported as a nickel(II)-templated Kagome metal-organic framework (MOF).

Purpose of the Study:

• To structurally reassign the reported Kagome MOF synthesis product.
• To investigate the feasibility of 1,4-diazacubane formation under reported experimental conditions.

Main Methods:

• Detailed analysis of the experimental procedure for MOF synthesis.
• Quantum chemical calculations to determine reaction enthalpies.
• Structural analysis and charge balance investigation.

Main Results:

• The synthesized Kagome MOF does not contain 1,4-diazacubane.
• Charge balance is achieved through disordered piperazinium cations occupying a twelve-fold symmetry site.
• Quantum chemical calculations indicate unfavorable enthalpies for 1,4-diazacubane formation.

Conclusions:

• The synthesis of 1,4-diazacubane remains unachieved.
• The previously reported synthesis requires structural correction.
• The stability and formation of azacubanes under specific conditions warrant further investigation.