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Redox‐Reversible 2D Metal–Organic Framework Nanosheets (MONs) Based on the Hydroquinone/Quinone Couple
Author(s) -
Maka Vijay Kumar,
Mukhopadhyay Arindam,
Jindal Swati,
Moorthy Jarugu Narasimha
Publication year - 2019
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201805188
Subject(s) - redox , hydroquinone , benzoquinone , quinone , ascorbic acid , polystyrene , chemistry , exfoliation joint , metal , materials science , photochemistry , combinatorial chemistry , nanotechnology , graphene , inorganic chemistry , organic chemistry , polymer , food science
Abstract 2D metal–organic nanosheets (MONs), akin to graphene, have aroused immense contemporary interest. In our quest to develop functional 2D MONs based on organic linkers designed de novo, we reasoned that benzene‐tetrabenzoic acid, which has been exploited tremendously in the construction of pillared metal–organic frameworks (MOFs), could be maneuvered readily to access redox‐active MONs based on the benzoquinone/hydroquinone redox couple. Herein, we show that the self‐assembly of 2,3,5,6‐tetrakis( p ‐carboxyphenyl)hydroquinone H 4 BTA with Zn(NO 3 ) 2 does lead to 2D metal–organic nanosheets that stack down the y axis, affording a layered Zn MOF. Although the crystals of the latter do not exhibit a discernible chemically induced redox switching behavior, the 2D MONs accessed by ultrasound‐induced liquid‐phase exfoliation (UILPE) lend themselves to a facile redox switching behavior. Treatment of a dispersion of the 2D MONs in methanol with phenyliodine(III) diacetate (PIDA) results in the oxidation of the hydroquinone core to benzoquinone. Remarkably, the latter can be reverted to the former by treatment with ascorbic acid as a reducing agent; indeed, the redox process can be made out by the naked eye. The results constitute the first example of chemically induced redox switching of 2D MONs. In view of emergent applications of 2D materials in general and MONs in particular, for example, improvement of the performance of membranes in separations by doping with MONs, the redox‐switchable property may lead to the development of unique materials with heretofore unexplored potential.