Title: | Post-Synthetic Modification of Zr-based Metal-Organic Frameworks with Imidazole: Variable Optical Behavior and Sensing |
Author(s): | Prakash Biswal D; Singha D; Panda J; Kumar Rana M; |
Address: | "Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER), Berhampur, Berhampur, 760010, Odisha, India" |
ISSN/ISBN: | 1439-7641 (Electronic) 1439-4235 (Linking) |
Abstract: | "UiO-66-NH(2) -IM, a fluorescent metal-organic framework (MOF), was synthesized by post-synthetic modification of UiO-66-NH(2) with 2-imidazole carboxaldehyde via a Schiff base reaction. It was examined using various characterization techniques (PXRD, FTIR, NMR, SEM, TGA, UV-Vis DRS, and photoluminescence spectroscopy). The emissive feature of UiO-66-NH(2) -IM was utilized to detect volatile organic compounds (VOCs), metal ions, and anions, such as acetone, Fe(3+) , and carbonate (CO(3) (2-) ). Acetone turns off the high luminescence of UiO-66-NH(2) -IM in DMSO, with the limit of detection (LOD) being 3.6 ppm. Similarly, Fe(3+) in an aqueous medium is detected at LOD=0.67 muM (0.04 ppm) via quenching. On the contrary, CO(3) (2-) in an aqueous medium significantly enhances the luminescence of UiO-66-NH(2) -IM, which is detected with extremely high sensitivity (LOD=1.16 muM, i. e., 0.07 ppm). Large Stern-Volmer constant, K(sv) , and low LOD values indicate excellent sensitivity of the post-synthetic MOF. Experimental data supported by density functional theory (DFT) calculations discern photo-induced electron transfer (PET), resonance energy transfer (RET), inner filter effect (IFE), or proton abstraction as putative sensing mechanisms. NMR and computational studies propose a proton abstraction mechanism for luminescence enhancement with CO(3) (2-) . Moreover, the optical behavior of the post-synthetic material toward analytes is recyclable" |
Keywords: | metal-organic framework optical sensing photoluminescence post-synthetic modification volatile organic compounds; |
Notes: | "PublisherPrakash Biswal, Dibya Singha, Dipankar Panda, Jagannath Kumar Rana, Malay eng DST/INSPIRE/04/2015/003103/DST/ Germany 2023/08/14 Chemphyschem. 2023 Aug 14:e202300311. doi: 10.1002/cphc.202300311" |