@article {46904, title = {Morphological evolution of two-dimensional porous hexagonal trimesic acid framework}, journal = {ACS Applied Materials \& Interfaces}, volume = {12}, year = {2020}, month = {APR }, pages = {15588-15594}, type = {Article}, abstract = {

Hexagonal single crystal structure (Form II) of trimesic acid (TMA) has been isolated by dissolving the interpenetrated Form I of TMA in tetrahydrofuran. Form II (hexagonal) was converted to Form I (interpenetrated) at room temperature through some intermediate structures. A detailed time-dependent FESEM study shows that the external morphology of Form II (hexagonal) is a hollow hexagonal tube that mimics its crystal structure. The block-shaped (morphology) of Form I (interpenetrated) was converted to the hollow hexagonal tube through some intermediate morphologies which are corresponding to particular crystal structures. Here, we have established a strong correlation between crystal structures with the morphology. These hollow tubes have been employed for Rhodamine B dye adsorption studies and showed an uptake of 82\%, much more significant than Form I (interpenetrated) (39\%) due to the presence of a pore channel in the crystal structure.

}, keywords = {dye adsorption, hollow hexagonal rod, hydrogen-bonded organic framework, morphology evaluation, trimesic acid}, issn = {1944-8244}, doi = {10.1021/acsami.0c01398}, author = {Tothadi, Srinu and Koner, Kalipada and Dey, Kaushik and Addicoat, Matthew and Banerjee, Rahul} } @article {48209, title = {Porous covalent organic nanotubes and their assembly in loops and toroids}, journal = {Nature Chemistry}, volume = {14}, year = {2022}, month = {MAY}, pages = {507+}, type = {Article}, abstract = {

Carbon nanotubes, and synthetic organic nanotubes more generally, have in recent decades been widely explored for application in electronic devices, energy storage, catalysis and biosensors. Despite noteworthy progress made in the synthesis of nanotubular architectures with well-defined lengths and diameters, purely covalently bonded organic nanotubes have remained somewhat challenging to prepare. Here we report the synthesis of covalently bonded porous organic nanotubes (CONTs) by Schiff base reaction between a tetratopic amine-functionalized triptycene and a linear dialdehyde. The spatial orientation of the functional groups promotes the growth of the framework in one dimension, and the strong covalent bonds between carbon, nitrogen and oxygen impart the resulting CONTs with high thermal and chemical stability. Upon ultrasonication, the CONTs form intertwined structures that go on to coil and form toroidal superstructures. Computational studies give some insight into the effect of the solvent in this assembly process.

}, issn = {1755-4330}, doi = {10.1038/s41557-022-00908-1}, author = {Koner, Kalipada and Karak, Shayan and Kandambeth, Sharath and Karak, Suvendu and Thomas, Neethu and Leanza, Luigi and Perego, Claudio and Pesce, Luca and Capelli, Riccardo and Moun, Monika and Bhakar, Monika and Ajithkumar, Thalasseril G. and Pavan, Giovanni M. and Banerjee, Rahul} } @article {48416, title = {Viscoelastic covalent organic nanotube fabric via macroscopic entanglement}, journal = {Journal of the American Chemical Society}, volume = {144}, year = {2022}, month = {SEP }, pages = {16052-16059}, type = {Article}, abstract = {

Covalent organic nanotubes (CONTs) are one-dimensional porous frameworks constructed from organic building blocks via dynamic covalent chemistry. CONTs are synthesized as insoluble powder that restricts their potential applications. The judicious selection of 2,2{\textquoteright}-bipyridine-5,5{\textquoteright}-dicarbaldehyde and tetraaminotriptycene as building blocks for TAT-BPy CONTs has led to constructing flexible yet robust and self-standing fabric up to 3 mu m thickness. The TAT-BPy CONTs and TAT-BPy CONT fabric have been characterized by solid-state one-dimensional (1D) C-13 CP-MAS, two-dimensional (2D) C-13-H-1 correlation NMR, 2D H-1-H-1 DQ-SQ NMR, and 2D N-14-H-1 correlation NMR spectroscopy. The mechanism of fabric formation has been established by using high-resolution transmission electron microscopy and scanning electron microscopy techniques. The as-synthesized viscoelastic TAT-BPy CONT fabric exhibits high mechanical strength with a reduced modulus (E-r) of 8 (+/- 3) GPa and hardness (H) of 0.6 (+/- 0.3) GPa. Interestingly, the viscoelastic fabric shows time-dependent elastic depth recovery up to 50-70\%.

}, issn = {0002-7863}, doi = {10.1021/jacs.2c06133}, author = {Koner, Kalipada and Das, Susobhan and Mohata, Shibani and Duong, Nghia Tuan and Nishiyama, Yusuke and Kandambeth, Sharath and Karak, Suvendu and Reddy, C. Malla and Banerjee, Rahul} }