@article { ISI:000234827500083, title = {Molecular dynamics simulations of H2O with sites of Cu-I-FAU and Cu-II-FAU}, journal = {Studies in surface science and catalysis }, volume = {158}, number = {A-B}, year = {2005}, note = {3rd Conference of the Federation-of-European-Zeolite-Association, Prague, CZECH REPUBLIC, AUG 23-29, 2005}, month = {OCT}, pages = {655-662}, publisher = {Elsevier Science}, type = {Article, Proceedings Paper}, address = {Prague, Czech Republic}, abstract = {

A Born Oppenheimer molecular dynamic (BOMD) approach was chosen to study the interaction of water molecules with Cu-FAU models. We have compared the reactivity of Cu-I and Cu-II with the zeolite and compared the results to those calculated for Na. This Study shows a decrease of the coordination with time for Cu-I whereas there is not a significant change for Cu-II. BOMD shows also that, in the presence of water, Na+ may lead to easier cation exchange than for transition metal cations.

}, isbn = {0-444-52082-1}, issn = {0167-2991}, doi = {10.1016/S0167-2991(05)80397-0}, author = {Berthomieu, D. and Krishnamurty, S. and Heine, Thomas and Goursot, A.}, editor = {Cejka, J. and Zilkova, N. and Nachtigall, P.} } @article { ISI:000328099400036, title = {Chemically stable multilayered covalent organic nanosheets from covalent organic frameworks via mechanical delamination}, journal = {Journal of the American Chemical Society}, volume = {135}, number = {47}, year = {2013}, month = {NOV}, pages = {17853-17861}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

A series of five thermally and chemically stable functionalized covalent organic frameworks (COFs), namely, TpPa-NO2, TpPa-F-4, TpBD-(NO2)(2), TpBD-Me-2, and TpBD-(OMe)(2) were synthesized by employing the solvothermal aldehyde-amine Schiff base condensation reaction. In order to complete the series, previously reported TpPa-1, TpPa-2, and TpBD have also been synthesized, and altogether, eight COFs were fully characterized through powder X-ray diffraction (PXRD), Fourier transform IR (FT-IR) spectroscopy, C-13 solid-state NMR spectroscopy, and thermogravimetric analysis. These COFs are crystalline, permanently porous, and stable in boiling water, acid (9 N HCl), and base (3 N NaOH). The. synthesized COFs (all eight) were successfully delaminated using a simple, safe, and environmentally friendly mechanical grinding route to transform into covalent organic nanosheets (CONs) and were well characterized via transmission electron microscopy and atomic force microscopy. Further PXRD and FT-IR analyses confirm that these CONs retain their structural integrity throughout the delamination process and also remain stable in aqueous, acidic, and basic media like the parent COFs. These exfoliated CONs have graphene-like layered morphology (delaminated layers), unlike the COFs from which they were synthesized.

}, issn = {0002-7863}, doi = {10.1021/ja408121p}, author = {Chandra, Suman and Kandambeth, Sharath and Biswal, Bishnu P. and Lukose, Binit and Kunjir, Shrikant M. and Chaudhary, Minakshi V. and BabaRao, Ravichandar and Heine, Thomas and Banerjee, Rahul} } @article { ISI:000327410300055, title = {Enhancement of chemical stability and crystallinity in porphyrin-containing covalent organic frameworks by intramolecular hydrogen bonds}, journal = {Angewandte Chemie-International Edition}, volume = {52}, number = {49}, year = {2013}, month = {DEC}, pages = {13052-13056}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, keywords = {covalent organic frameworks, hydrogen bonds, mesoporous materials, porphyrinoids, tautomerism}, issn = {1433-7851}, doi = {10.1002/anie.201306775}, author = {Kandambeth, Sharath and Shinde, Digambar Balaji and Panda, Manas K. and Lukose, Binit and Heine, Thomas and Banerjee, Rahul} } @article { ISI:000317548400026, title = {Mechanochemical synthesis of chemically stable isoreticular covalent organic frameworks}, journal = {Journal of the American Chemical Society}, volume = {135}, number = {14}, year = {2013}, month = {APR}, pages = {5328-5331}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Three thermally and chemically stable isoreticular covalent organic frameworks (COFs) were synthesized via room-temperature solvent-free mechanochemical grinding. These COFs were successfully compared with their solvothermally synthesized counterparts in all aspects. These solvent-free mechanochemically synthesized COFs have moderate crystallinity with remarkable stability in boiling water, acid (9 N HCl), and base [TpBD (MC) in 3 N NaOH and TpPa-2 (MC) in 9 N NaOH]. Exfoliation of COF layers was simultaneously observed with COF formation during mechanochemical synthesis. The structures thus obtained seemed to have a graphene-like layered morphology (exfoliated layers), unlike the parent COFs synthesized solvothermally.

}, issn = {0002-7863}, doi = {10.1021/ja4017842}, author = {Biswal, Bishnu P. and Chandra, Suman and Kandambeth, Sharath and Lukose, Binit and Heine, Thomas and Banerjeet, Rahul} } @article { ISI:000356176200034, title = {Chemical sensing in two dimensional porous covalent organic nanosheets}, journal = {Chemical Science}, volume = {6}, number = {7}, year = {2015}, month = {APR}, pages = {3931-3939}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

Two new imide-based crystalline, porous, and chemically stable covalent organic frameworks (COFs) (TpBDH and TfpBDH) have been successfully synthesized employing solvothermal crystallization route. Furthermore, thin layered covalent organic nanosheets (CONs) were derived from these bulk COFs by the simple liquid phase exfoliation method. These 2D CONs showcase increased luminescence intensity compared to their bulk counterparts (COFs). Notably, TfpBDH-CONs showcase good selectivity and prominent, direct visual detection towards different nitroaromatic analytes over TpBDH-CONs. Quite interestingly, TfpBDH-CONs exhibit a superior {\textquoteleft}{\textquoteleft}turn-on{\textquoteright}{\textquoteright} detection capability for 2,4,6-trinitrophenol (TNP) in the solid state, but conversely, they also show a {\textquoteleft}{\textquoteleft}turn-off{\textquoteright}{\textquoteright} detection in the dispersion state. These findings describe a new approach towards developing an efficient, promising fluorescence chemosensor material for both visual and spectroscopic detection of nitroaromatic compounds with very low [10(-5) (M)] analyte concentrations.

}, issn = {2041-6520}, doi = {10.1039/c5sc00512d}, author = {Das, Gobinda and Biswal, Bishnu P. and Kandambeth, Sharath and Venkatesh, V. and Kaur, Gagandeep and Addicoat, Matthew A. and Heine, Thomas and Verma, Sandeep and Banerjee, Rahul} } @article { ISI:000348147100072, title = {Solid state organic amine detection in a photochromic porous metal organic framework}, journal = {Chemical Science}, volume = {6}, number = {2}, year = {2015}, month = {DEC}, pages = {1420-1425}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

A new Mg(II) based photochromic porous metal-organic framework (MOF) has been synthesized bearing naphthalenediimide (NDI) chromophoric unit. This MOF (Mg-NDI) shows instant and reversible solvatochromic behavior in presence of solvents with different polarity. Mg-NDI also exhibits fast and reversible photochromism via radical formation. Due to the presence of electron deficient NDI moiety, this MOF exhibits selective organic amine (electron rich) sensing in solid state. The organic amine detection has been confirmed by photoluminescence quenching experiment and visual color change.

}, issn = {2041-6520}, doi = {10.1039/c4sc03224a}, author = {Mallick, Arijit and Garai, Bikash and Addicoat, Matthew A. and Petkov, Petko St. and Heine, Thomas and Banerjee, Rahul} } @article {43030, title = {Decoding the morphological diversity in two dimensional crystalline porous polymers by core planarity modulation}, journal = {Angewandte Chemie - International Edition}, volume = {55}, year = {2016}, month = {JUN}, pages = {7806-7810}, doi = {10.1002/anie.201600087}, author = {Halder, Arjun and Kandambeth, Sharath and Biswal, Bishnu P. and Kaur, Gagandeep and Roy, Neha Chaki and Addicoat, Matthew A. and Salunke, Jagadish K. and Banerjee, Subhrashis and Vanka, Kumar and Heine, Thomas and Verma, Sandeep and Banerjee, Rahul} } @article { ISI:000371852000031, title = {Interplaying intrinsic and extrinsic proton conductivities in covalent organic frameworks}, journal = {Chemistry of Materials}, volume = {28}, number = {5}, year = {2016}, month = {MAR}, pages = {1489-1494}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

A sulfonic-acid-based covalent organic framework (TpPa-SO3H) has been synthesized that exhibits intrinsic proton conductivity under anhydrous conditions. The sulfonic acid groups are aligned on the two-dimensional (2D) layers at periodic intervals and promote the proton hopping inside the hexagonal one-dimensional channel. The intrinsic proton conductivity of TpPa-SO3H was measured as 1.7 X 10(-5) S cm(-1) at 120 degrees C under anhydrous conditions. To enhance the proton conductivity, we have synthesized a hybrid COF TpPa(SO3H-Py) by a ligand-based solid-solution approach that contains sulfonic acid as the acidic site, as well as pyridine as the basic site, in order to immobilize acidic proton carrier molecules. Impregnation of phytic acid molecules inside the framework increases the anhydrous proton conductivity up to 5 x 10(-4) S cm(-1) at 120 degrees C. Such an approach highlights the advantage and first-time use of hybrid COF for interplaying intrinsic to extrinsic proton conductivity.

}, issn = {0897-4756}, doi = {10.1021/acs.chemmater.5b04947}, author = {Chandra, Suman and Kundu, Tanay and Dey, Kaushik and Addicoat, Matthew A. and Heine, Thomas and Banerjee, Rahul} } @article {44375, title = {Ultrastable imine-based covalent organic frameworks for sulfuric acid recovery: an effect of interlayer hydrogen bonding}, journal = {Angewandte Chemie-International Edition}, volume = {57}, year = {2018}, month = {MAY}, pages = {5797-5802}, abstract = {A rapid and scalable synthesis of six new imine-linked highly porous and crystalline COFs is presented that feature exceptionally high chemical stability in harsh environments including conc. H2SO4 (18M), conc. HCl (12M), and NaOH (9M). This is because of the presence of strong interlayer C-H center dot center dot center dot N hydrogen bonding among the individual layers, which provides significant steric hindrance and a hydrophobic environment around the imine (-C=N-) bonds, thus preventing their hydrolysis in such an abrasive environment. These COFs were further converted into porous, crystalline, self-standing, and crack-free COF membranes (COFMs) with extremely high chemical stability for their potential applications for sulfuric acid recovery. The as-synthesized COFMs exhibit unprecedented permeance for acetonitrile (280 Lm(-2) h(-1) bar(-1)) and acetone (260 Lm(-2) h(-1) bar(-1)).}, doi = {10.1002/anie.201802220}, author = {Halder, Arjun and Karak, Suvendu and Addicoat, Matthew and Bera, Saibal and Chakraborty, Amit and Kunjattu, Shebeeb H. and Pachfule, Pradip and Heine, Thomas and Banerjee, Rahul} } @article {48833, title = {Covalent organic framework thin-film photodetectors from solution-processable porous nanospheres}, journal = {Journal of the American Chemical Society}, volume = {145}, year = {2023}, month = {JAN}, pages = {1649-1659}, type = {Article}, abstract = {

The synthesis of homogeneous covalent organic framework (COF) thin films on a desired substrate with decent crystallinity, porosity, and uniform thickness has great potential for optoelectronic applications. We have used a solution-processable sphere transmutation process to synthesize 300 +/- 20 nm uniform COF thin films on a 2 x 2 cm2 TiO2-coated fluorine-doped tin oxide (FTO) surface. This process controls the nucleation of COF crystallites and molecular morphology that helps the nanospheres to arrange periodically to form homogeneous COF thin films. We have synthesized four COF thin films (TpDPP, TpEtBt, TpTab, and TpTta) with different functional backbones. In a close agreement between the experiment and density functional theory, the TpEtBr COF film showed the lowest optical band gap (2.26 eV) and highest excited-state lifetime (8.52 ns) among all four COF films. Hence, the TpEtBr COF film can participate in efficient charge generation and separation. We constructed optoelectronic devices having a glass/FTO/TiO2/COF-film/Au architecture, which serves as a model system to study the optoelectronic charge transport properties of COF thin films under dark and illuminated conditions. Visible light with a calibrated intensity of 100 mW cm-2 was used for the excitation of COF thin films. All of the COF thin films exhibit significant photocurrent after illumination with visible light in comparison to the dark. Hence, all of the COF films behave as good photoactive substrates with minimal pinhole defects. The fabricated out-of-plane photodetector device based on the TpEtBr COF thin film exhibits high photocurrent density (2.65 +/- 0.24 mA cm-2 at 0.5 V) and hole mobility (8.15 +/- 0.64 x10-3 cm2 V-1 S-1) compared to other as synthesized films, indicating the best photoactive characteristics.

}, issn = {0002-7863}, doi = {10.1021/jacs.2c09838}, author = {Bag, Saikat and Sasmal, Himadri Sekhar and Chaudhary, Sonu Pratap and Dey, Kaushik and Blaette, Dominic and Guntermann, Roman and Zhang, Yingying and Poloz, Miroslav and Kuc, Agnieszka and Shelke, Ankita and Vijayaraghavan, Ratheesh K. and Ajithkumar, Thalasseril G. and Bhattacharyya, Sayan and Heine, Thomas and Bein, Thomas and Banerjee, Rahul} }