Cobalt(II)‐dianthracene Frameworks: Assembly, Exfoliation and Properties

Abstract

Abstract Metal‐organic frameworks containing responsive organic linkers are attractive for potential applications in sensors and molecular devices. Herein we report three cobalt(II) phosphonates incorporating responsive dianthracene linkers, namely, Co 2 (amp 2 H 2 ) 2 (H 2 O) 4 ⋅ 6H 2 O ( MDAF‐1 ), Co 2 (amp 2 )(H 2 O) 4 ⋅ 2H 2 O ( MDAF‐2 ) and Co(amp 2 H 2 ) ⋅ 2H 2 O ⋅ 0.5DMF ( MDAF‐3 ), where amp 2 H 4 is pre‐photodimerized 9‐anthrylmethylphosphonic acid. MDAF‐1 shows a layer structure in which dinuclear Co 2 (PO 3 H) 2 units are inter‐connected by dianthracene ligands. In MDAF‐2 and MDAF‐3 , inorganic chains of corner‐sharing {CoO 4 } (or {CoO 6 }) and {PO 3 C} are cross‐linked by dianthracene ligands into 3D frameworks. All compounds underwent thermo‐induced phase transitions, first the de‐solvation and then the de‐dimerization of dianthracene (as well as the release of the remaining solvent molecules for MDAF‐2 and ‐3 ), associated with magnetic changes. MDAF‐1 can be exfoliated into single‐layer nanosheets in water which show light‐triggered luminescent changes.