1,6;2,3-Bis-BN Cyclohexane: Synthesis, Structure, and Hydrogen Release

Area of Science:

• * Inorganic Chemistry
• * Organic Chemistry
• * Materials Science

Background:

• * Boron-nitrogen (BN) isosterism is a key strategy for developing novel carbon-based compounds with unique properties.
• * Introducing BN units into organic molecules leads to significant alterations in their characteristics.
• * Cyclohexane is a fundamental cyclic alkane, and its structural and energetic properties are well-understood.

Purpose of the Study:

• * To report the first synthesis and characterization of 1,6;2,3-bis-BN cyclohexane, a novel isostere of cyclohexane.
• * To investigate the conformational properties, specifically the ring flipping barrier, of this new BN-containing compound.
• * To evaluate the hydrogen storage potential of 1,6;2,3-bis-BN cyclohexane and compare it with its isomers.

Main Methods:

• * Synthesis of 1,6;2,3-bis-BN cyclohexane.
• * Characterization using spectroscopic and analytical techniques.
• * Computational studies to determine the ring flipping barrier.
• * Hydrogen storage capacity measurements via gravimetric analysis.

Main Results:

• * Successful synthesis and characterization of 1,6;2,3-bis-BN cyclohexane, featuring two adjacent BN pairs.
• * The ring flipping barrier of 1,6;2,3-bis-BN cyclohexane was found to be comparable to that of cyclohexane.
• * Protic hydrogens on nitrogen atoms exhibited higher reactivity compared to isomeric bis-BN cyclohexane compounds.
• * Achieved a significant hydrogen storage capacity of over 9.0 wt %, nearly double that of 1,2;4,5-bis-BN cyclohexane.

Conclusions:

• * 1,6;2,3-bis-BN cyclohexane represents a novel BN isostere of cyclohexane with unique properties.
• * The compound maintains a similar ring dynamics to cyclohexane while offering enhanced reactivity and superior hydrogen storage capabilities.
• * This work expands the scope of BN isosterism in organic chemistry and highlights potential applications in hydrogen storage materials.