Layer defoliation and slippery of triformylphloroglucinol-covalent organic framework under pH stress

作者：Tsai, Ruei-Wei; Chang, Jo-Shu; Wu, Rome-Ming; Lee, Duu-Jong^*

来源：Materials Letters, 2023, 351: 135059.

DOI：10.1016/j.matlet.2023.135059

• Keto-enamine COF
• Amorphous material
• Crystal
• Exfoliation
• Stability

The triformylphloroglucinol covalent organic framework is a keto-enamine-based porous matrix generally presented as two-dimensional layers stacked to form a superstructure. This study aims to compare the layer stability for three Tp-COFs, two from triformylphloroglucinol and compounds containing the 2,5-diamino structure, TpPa (OH)2 and TpPaSO3Na, and another from triformylphloroglucinol and biuret, called TpBu. The pH -0.2 stresses moderately slip the TpPa(OH)2 layers, while pH 14 stress leads to severe layer slippery to deteriorate its longrange crystal structure. The excess protons protonate the sulfite group of TpPaSO3Na, weaken the H bonds between amine and S-O groups, and make the pH -0.2 stress layer slippery. The layer stability of Tp-COFs correlates with the H bonds formed with the amine groups. The TpBu has excessive amine groups, hence having the highest layer stability.