Triptycene-based 2.5D Metal-Organic Frameworks: Atomically Ac-curate Structures and One-Dimensional Antiferromagnetism from Hydrogen-Bonding Bridged Protonated Building Units

04 November 2024, Version 1
This content is a preprint and has not undergone peer review at the time of posting.

Abstract

Recent advances in two-dimensional π-d conjugated conductive metal-organic frameworks (2D cMOFs) have highlighted their potential as sophisticated, active materials in electrochemical energy storage devices, electrocatalysis, and sensors. However, a lack of high-quality structural characterization severely limits understanding their physical properties. Specifically, rapid and irre-versible nucleation and aggregation, induced by strong interlayer π-π interactions, have hindered crystal growth in these cMOFs. In this study, by utilizing triptycene-based ligands, 2,3,6,7,14,15-hexahydroxy triptycene (HHTripH2) and 9,10-dimethyl-2,3,6,7,14,15-hexahydroxy triptycene (HHTripMe2), we successfully mitigated interlayer π-π interactions and achieved SCXRD quality crystals of two triptycene-based 2D MOFs: Cu3(TripH2)2 and Cu3(TripMe2)2. The crystal structures reveal a protonated catechol ligand and an interlayer hydrogen-bonding-guided stacking motif. Notably, the steric effect of the two axial methyl groups in the TripMe2 ligand modifies the structure of Cu3(TripMe2)2 from regular AB stacking to interpenetration, significantly enhancing the stability of the crystals. ESR and susceptibility measurements indicate that these modifications facilitate hydrogen-bonding-guided 1D antiferromagnetic behavior in the Cu(cat)2 secondary building units (SBUs). This study reveals the critical roles of high-quality crystal structures and protonation/deprotonation of coordinating atoms in understanding the properties of 2D MOFs.

Keywords

2.5-Dimensional MOFs
Single Crystal
1D Antiferromagnetism
Electron Spin Resonance

Supplementary materials

Title
Description
Actions
Title
Supporting Information
Description
Supporting Information
Actions
Title
Cif file for Cu3(TripH2)2
Description
Cif file for Cu3(TripH2)2
Actions
Title
Cif file for Cu3(TripMe2)2
Description
Cif file for Cu3(TripMe2)2
Actions

Comments

Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.