Solvent-assisted delamination of layered copper dithienothiophene-dicarboxylate (DUT-134)

Abstract

The isolation of 2D nanosheets of layered metal-organic frameworks (MOFs) has become an active research field, due to the various advantages resulting from shape anisotropy. The most sophisticated method to...

Cooperative Assembly of 2D‐MOF Nanoplatelets into Hierarchical Carpets and Tubular Superstructures for Advanced Air Filtration

“…The ED pattern of [100] zone, obtained from a single crystallite of the carpet (Figure 5c), confirms the structural integrity of the material. The solvent‐free DUT‐134 crystallizes in a monoclinic space group P 2 1 /m with unit cell parameters a =13.309 Å, b =26.831 Å, c =28.169 Å, and β =96.59° [22] . The values obtained from the experimental electron diffraction pattern of the [100] zone are 27.5 and 27.1 Å and are thus in reasonable agreement.…”

“…The solvent-free DUT-134 crystallizes in a monoclinic space group P2 1 /m with unit cell parameters a = 13.309 Å, b = 26.831 Å, c = 28.169 Å, and β = 96.59°. [22] The values obtained from the experimental electron diffraction pattern of Despite the exact formation mechanism of the carpets from the suspension of platelets may require further investigations, we propose the following assembly mechanism: Crystallites obtained in quasi-interfacial synthesis attach to the glass walls of the reaction tube, acting as substrate. The DMF supported assembly leads to the formation of the films, which detach from the glass surface easily to form freestanding carpets.…”

“…Supercritically dried DUT-134(Cu) bulk crystals offer a specific BET area of 1200 m 2 g À 1 and a pore volume of 0.54 cm 3 g À 1 (as derived from nitrogen adsorption isotherms measured at 77 K). [22] Adsorption characteristics of the dried carpets are accessible via krypton adsorption, a probe suitable for the investigation of small amounts of material or materials with an extremely small surface area. For krypton physisorption at 77 K, due to the extremely low saturation pressure of 0.35 kPa, the number of molecules in the free space of the sample cell can be significantly reduced, which enables the high sensitivity of the krypton measurement.…”

“…[21] DUT-134(Cu) is an ideal 2D model system, a typical representative of layered MOFs based on paddle wheel as secondary building unit (Figure 1). [22] Copper paddle wheels interlinked by the ditopic dithieno[3,2-b : 2',3'-d]thiophene-2,6-dicarboxylate (dttc 2À ) linker form undulated layers with the (4,4)-net structure. The axial positions of the paddle wheels in DUT-134(Cu)•DMF are coordinated by N,Ndimethylformamide (DMF) molecules, resulting in a framework with overall composition [Cu 2 (dttc) 2 (DMF) 2 (L) x ] n , (L represents the solvent in the pores in addition to the solvent coordinated to the paddle wheels) (Figure S3, Supporting Information).…”

“…Upon desolvation a structural transformation reduces the interlayer distance to 6.1 Å resulting in an AA stacking (Figure 1). [22] This structural transformation leads to effective shielding of the axial positions of the paddle wheels (open metal sites), making them hardly accessible for catalytic applications or chemisorptive air filtration. The inaccessibility of planar surfaces in 2D materials due to packing is a key challenge considering 2D materials for real world applications.…”