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Sensharma, Debobroto

Publications and source records attributed to Sensharma, Debobroto.

Crystal Engineering of Two Light and Pressure Responsive Physisorbents

Abstract An emerging strategy in the design of efficient gas storage technologies is the development of stimuli‐responsive physisorbents which undergo transformations in response to a particular stimulus, such as pressure, heat or light. Herein, we report two isostructural light modulated adsorbents (LMAs) containing bis‐3‐thienylcyclopentene (BTCP), LMA‐1 [Cd(BTCP)(DPT) 2 ] (DPT=2,5‐diphenylbenzene‐1,4‐dicarboxylate) and LMA‐2 [Cd(BTCP)(FDPT) 2 ] (FDPT=5‐fluoro‐2,diphenylbenzene‐1,4‐dicarboxylate). Both LMAs undergo pressure induced switching transformations from non‐porous to porous via adsorption of N 2 , CO 2 and C 2 H 2 . LMA‐1 exhibited multi‐step adsorption while LMA‐2 showed a single‐step adsorption isotherm. The light responsive nature of the BTPC ligand in both frameworks was exploited with irradiation of LMA‐1 resulting in a 55 % maximum reduction of CO 2 uptake at 298 K. This study reports the first example of a switching sorbent (closed to open) that can be further modulated by light.

Castell, Dominic C.↗

Crystal Engineering of Two Light and Pressure Responsive Physisorbents

Abstract An emerging strategy in the design of efficient gas storage technologies is the development of stimuli‐responsive physisorbents which undergo transformations in response to a particular stimulus, such as pressure, heat or light. Herein, we report two isostructural light modulated adsorbents (LMAs) containing bis‐3‐thienylcyclopentene (BTCP), LMA‐1 [Cd(BTCP)(DPT) 2 ] (DPT=2,5‐diphenylbenzene‐1,4‐dicarboxylate) and LMA‐2 [Cd(BTCP)(FDPT) 2 ] (FDPT=5‐fluoro‐2,diphenylbenzene‐1,4‐dicarboxylate). Both LMAs undergo pressure induced switching transformations from non‐porous to porous via adsorption of N 2 , CO 2 and C 2 H 2 . LMA‐1 exhibited multi‐step adsorption while LMA‐2 showed a single‐step adsorption isotherm. The light responsive nature of the BTPC ligand in both frameworks was exploited with irradiation of LMA‐1 resulting in a 55 % maximum reduction of CO 2 uptake at 298 K. This study reports the first example of a switching sorbent (closed to open) that can be further modulated by light.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Reversible transformations between the non-porous phases of a flexible coordination network enabled by transient porosity

Abstract Flexible metal–organic materials that exhibit stimulus-responsive switching between closed (non-porous) and open (porous) structures induced by gas molecules are of potential utility in gas storage and separation. Such behaviour is currently limited to a few dozen physisorbents that typically switch through a breathing mechanism requiring structural contortions. Here we show a clathrate (non-porous) coordination network that undergoes gas-induced switching between multiple non-porous phases through transient porosity, which involves the diffusion of guests between discrete voids through intra-network distortions. This material is synthesized as a clathrate phase with solvent-filled cavities; evacuation affords a single-crystal to single-crystal transformation to a phase with smaller cavities. At 298 K, carbon dioxide, acetylene, ethylene and ethane induce reversible switching between guest-free and gas-loaded clathrate phases. For carbon dioxide and acetylene at cryogenic temperatures, phases showing progressively higher loadings were observed and characterized using in situ X-ray diffraction, and the mechanism of diffusion was computationally elucidated.

Chemistry↗

CO 2 Capture by Hybrid Ultramicroporous TIFSIX‐3‐Ni under Humid Conditions Using Non‐Equilibrium Cycling

Abstract Although pyrazine‐linked hybrid ultramicroporous materials (HUMs, pore size <7 Å) are benchmark physisorbents for trace carbon dioxide (CO 2 ) capture under dry conditions, their affinity for water (H 2 O) mitigates their carbon capture performance in humid conditions. Herein, we report on the co‐adsorption of H 2 O and CO 2 by TIFSIX‐3‐Ni—a high CO 2 affinity HUM—and find that slow H 2 O sorption kinetics can enable CO 2 uptake and release using shortened adsorption cycles with retention of ca. 90 % of dry CO 2 uptake. Insight into co‐adsorption is provided by in situ infrared spectroscopy and ab initio calculations. The binding sites and sorption mechanisms reveal that both CO 2 and H 2 O molecules occupy the same ultramicropore through favorable interactions between CO 2 and H 2 O at low water loading. An energetically favored water network displaces CO 2 molecules at higher loading. Our results offer bottom‐up design principles and insight into co‐adsorption of CO 2 and H 2 O that is likely to be relevant across the full spectrum of carbon capture sorbents to better understand and address the challenge posed by humidity to gas capture.

Ullah, Saif↗

CO 2 Capture by Hybrid Ultramicroporous TIFSIX‐3‐Ni under Humid Conditions Using Non‐Equilibrium Cycling

Abstract Although pyrazine‐linked hybrid ultramicroporous materials (HUMs, pore size <7 Å) are benchmark physisorbents for trace carbon dioxide (CO 2 ) capture under dry conditions, their affinity for water (H 2 O) mitigates their carbon capture performance in humid conditions. Herein, we report on the co‐adsorption of H 2 O and CO 2 by TIFSIX‐3‐Ni—a high CO 2 affinity HUM—and find that slow H 2 O sorption kinetics can enable CO 2 uptake and release using shortened adsorption cycles with retention of ca. 90 % of dry CO 2 uptake. Insight into co‐adsorption is provided by in situ infrared spectroscopy and ab initio calculations. The binding sites and sorption mechanisms reveal that both CO 2 and H 2 O molecules occupy the same ultramicropore through favorable interactions between CO 2 and H 2 O at low water loading. An energetically favored water network displaces CO 2 molecules at higher loading. Our results offer bottom‐up design principles and insight into co‐adsorption of CO 2 and H 2 O that is likely to be relevant across the full spectrum of carbon capture sorbents to better understand and address the challenge posed by humidity to gas capture.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗