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Two-dimensional, conductive niobium and molybdenum metal–organic frameworks
The incorporation of second-row transition metals into metal–organic frameworks could greatly improve the performance of these materials across a wide variety of applications due to the enhanced covalency, redox activity, and spin–orbit coupling of late-row metals relative to their first-row analogu...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Royal Society of Chemistry
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7481840/ https://www.ncbi.nlm.nih.gov/pubmed/32953030 http://dx.doi.org/10.1039/d0sc02515a |
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author | Ziebel, Michael E. Ondry, Justin C. Long, Jeffrey R. |
author_facet | Ziebel, Michael E. Ondry, Justin C. Long, Jeffrey R. |
author_sort | Ziebel, Michael E. |
collection | PubMed |
description | The incorporation of second-row transition metals into metal–organic frameworks could greatly improve the performance of these materials across a wide variety of applications due to the enhanced covalency, redox activity, and spin–orbit coupling of late-row metals relative to their first-row analogues. Thus far, however, the synthesis of such materials has been limited to a small number of metals and structural motifs. Here, we report the syntheses of the two-dimensional metal–organic framework materials (H(2)NMe(2))(2)Nb(2)(Cl(2)dhbq)(3) and Mo(2)(Cl(2)dhbq)(3) (H(2)Cl(2)dhbq = 3,6-dichloro-2,5-dihydroxybenzoquinone), which feature mononuclear niobium or molybdenum metal nodes and are formed through reactions driven by metal-to-ligand electron transfer. Characterization of these materials via X-ray absorption spectroscopy suggests a local trigonal prismatic coordination geometry for both niobium and molybdenum, consistent with their increased covalency relative to related first-row transition metal compounds. A combination of vibrational spectroscopy, magnetic susceptibility, and electronic conductivity measurements reveal that these two frameworks possess distinct electronic structures. In particular, while the niobium compound displays evidence for redox-trapping and strong magnetic interactions, the molybdenum phase is valence-delocalized with evidence of large polaron formation. Weak interlayer interactions in the neutral molybdenum phase enable solvent-assisted exfoliation to yield few-layer hexagonal nanosheets. Together, these results represent the first syntheses of metal–organic frameworks containing mononuclear niobium and molybdenum nodes, establishing a route to frameworks incorporating a more diverse range of second- and third-row transition metals with increased covalency and the potential for improved charge transport and stronger magnetic coupling. |
format | Online Article Text |
id | pubmed-7481840 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | Royal Society of Chemistry |
record_format | MEDLINE/PubMed |
spelling | pubmed-74818402020-09-18 Two-dimensional, conductive niobium and molybdenum metal–organic frameworks Ziebel, Michael E. Ondry, Justin C. Long, Jeffrey R. Chem Sci Chemistry The incorporation of second-row transition metals into metal–organic frameworks could greatly improve the performance of these materials across a wide variety of applications due to the enhanced covalency, redox activity, and spin–orbit coupling of late-row metals relative to their first-row analogues. Thus far, however, the synthesis of such materials has been limited to a small number of metals and structural motifs. Here, we report the syntheses of the two-dimensional metal–organic framework materials (H(2)NMe(2))(2)Nb(2)(Cl(2)dhbq)(3) and Mo(2)(Cl(2)dhbq)(3) (H(2)Cl(2)dhbq = 3,6-dichloro-2,5-dihydroxybenzoquinone), which feature mononuclear niobium or molybdenum metal nodes and are formed through reactions driven by metal-to-ligand electron transfer. Characterization of these materials via X-ray absorption spectroscopy suggests a local trigonal prismatic coordination geometry for both niobium and molybdenum, consistent with their increased covalency relative to related first-row transition metal compounds. A combination of vibrational spectroscopy, magnetic susceptibility, and electronic conductivity measurements reveal that these two frameworks possess distinct electronic structures. In particular, while the niobium compound displays evidence for redox-trapping and strong magnetic interactions, the molybdenum phase is valence-delocalized with evidence of large polaron formation. Weak interlayer interactions in the neutral molybdenum phase enable solvent-assisted exfoliation to yield few-layer hexagonal nanosheets. Together, these results represent the first syntheses of metal–organic frameworks containing mononuclear niobium and molybdenum nodes, establishing a route to frameworks incorporating a more diverse range of second- and third-row transition metals with increased covalency and the potential for improved charge transport and stronger magnetic coupling. Royal Society of Chemistry 2020-06-02 /pmc/articles/PMC7481840/ /pubmed/32953030 http://dx.doi.org/10.1039/d0sc02515a Text en This journal is © The Royal Society of Chemistry 2020 http://creativecommons.org/licenses/by/3.0/ This article is freely available. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence (CC BY 3.0) |
spellingShingle | Chemistry Ziebel, Michael E. Ondry, Justin C. Long, Jeffrey R. Two-dimensional, conductive niobium and molybdenum metal–organic frameworks |
title | Two-dimensional, conductive niobium and molybdenum metal–organic frameworks
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title_full | Two-dimensional, conductive niobium and molybdenum metal–organic frameworks
|
title_fullStr | Two-dimensional, conductive niobium and molybdenum metal–organic frameworks
|
title_full_unstemmed | Two-dimensional, conductive niobium and molybdenum metal–organic frameworks
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title_short | Two-dimensional, conductive niobium and molybdenum metal–organic frameworks
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title_sort | two-dimensional, conductive niobium and molybdenum metal–organic frameworks |
topic | Chemistry |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7481840/ https://www.ncbi.nlm.nih.gov/pubmed/32953030 http://dx.doi.org/10.1039/d0sc02515a |
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