| Autor: |
Celis-Salazar PJ; Department of Chemistry, Virginia Tech , Blacksburg, Virginia 24061, United States., Epley CC; Department of Chemistry, Virginia Tech , Blacksburg, Virginia 24061, United States., Ahrenholtz SR; Department of Chemistry, Virginia Tech , Blacksburg, Virginia 24061, United States., Maza WA; Department of Chemistry, Virginia Tech , Blacksburg, Virginia 24061, United States., Usov PM; Department of Chemistry, Virginia Tech , Blacksburg, Virginia 24061, United States., Morris AJ; Department of Chemistry, Virginia Tech , Blacksburg, Virginia 24061, United States. |
| Jazyk: |
angličtina |
| Zdroj: |
Inorganic chemistry [Inorg Chem] 2017 Nov 20; Vol. 56 (22), pp. 13741-13747. Date of Electronic Publication: 2017 Nov 02. |
| DOI: |
10.1021/acs.inorgchem.7b01656 |
| Abstrakt: |
The ditopic ligands 2,6-dicarboxy-9,10-anthraquinone and 1,4-dicarboxy-9,10-anthraquinone were used to synthesize two new UiO-type metal-organic frameworks (MOFs; namely, 2,6-Zr-AQ-MOF and 1,4-Zr-AQ-MOF, respectively). The Pourbaix diagrams (E vs pH) of the MOFs and their ligands were constructed using cyclic voltammetry in aqueous buffered media. The MOFs exhibit chemical stability and undergo diverse electrochemical processes, where the number of electrons and protons transferred was tailored in a Nernstian manner by the pH of the media. Both the 2,6-Zr-AQ-MOF and its ligand reveal a similar electrochemical pK a value (7.56 and 7.35, respectively) for the transition between a two-electron, two-proton transfer (at pH < pK a ) and a two-electron, one-proton transfer (at pH > pK a ). In contrast, the position of the quinone moiety with respect to the zirconium node, the effect of hydrogen bonding, and the amount of defects in 1,4-Zr-AQ-MOF lead to the transition from a two-electron, three-proton transfer to a two-electron, one-proton transfer. The pK a of this framework (5.18) is analogous to one of the three electrochemical pK a values displayed by its ligand (3.91, 5.46, and 8.80), which also showed intramolecular hydrogen bonding. The ability of the MOFs to tailor discrete numbers of protons and electrons suggests their application as charge carriers in electronic devices. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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