Homoconjugation-Enabled Kagome Bands in a Layer-Decoupled Two-Dimensional Conductive Triptycene-Based Metal-Organic...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Chemistry

Background:

• Two-dimensional (2D) conductive metal-organic frameworks (MOFs) exhibit in-plane electronic delocalization via π-d conjugation and out-of-plane transport through interlayer π-π interactions.
• Interlayer interactions in most 2D MOFs cause stacking-dependent properties, leading to variability and obscuring intrinsic behavior.

Purpose of the Study:

• To design and synthesize 2D MOFs that suppress interlayer coupling, preserving intrinsic electronic topology in bulk materials.
• To investigate the electronic and transport properties of these novel MOFs and understand the underlying mechanisms.

Main Methods:

• Synthesis of triptycene-based Ni-hexaiminophenylene frameworks (Ni3(HITrip)2).
• Characterization of structural, electronic, and transport properties.
• Density functional theory (DFT) calculations to elucidate electronic topology and transport mechanisms.

Main Results:

• Successfully synthesized Ni3(HITrip)2, a 2D MOF with effectively eliminated interlayer π-π coupling.
• Achieved high bulk electrical conductivity (0.58 S cm-1) with a finite band gap and large surface area.
• Observed strongly anisotropic transport and preserved in-plane electronic topology independent of stacking arrangement.

Conclusions:

• The triptycene-based linker design effectively suppresses interlayer coupling in 2D MOFs.
• This strategy enables the realization of monolayer-like electronic structures in stacked materials.
• Provides a robust platform for low-dimensional 2D MOF electronics and topological studies, particularly for kagome lattices.