Lewis basic DABCO-functionalized 3D-like metal-organic framework, Zn-MOF, catalyzes nitroaldol (Henry) reaction of 4-nitrobenzaldehyde with nitroalkanes in a size-dependent manner. Small nitroalkanes give rise to higher conversion than larger ones. This MOF-based heterogeneous catalyst is very robust and can be recycled several times without losing its activity.
A Zn-MOF assembled from a new C(2h)-symmetric terphenyl dicarboxylate and DABCO was prepared and characterized by X-ray crystallography and gas sorption analysis: a preferential sorption of CO(2) over N(2) and H(2) was observed with an exceptionally high CO(2) adsorption enthalpy.
The reaction between 1,3,5-benzenetribenzoic acid (H 3 BTB) and In(NO 3 ) 3 hydrate in diethylformamide yielded a new In III -metal-organic framework, [(CH 3 CH 2 ) 2 NH 2 ] 3 [In 3 (BTB) 4 ]•10DEF•14H 2 O (I). The countercation and solvent-free doubly interpenetrated I potentially contains 71.0% of solvent accessible void. Although the framework of I was not stable enough to maintain its original structure when the solvent molecules were removed, the as-prepared I was found to be a very good sorbent for acridine orange hydrochloride, a large Reichardt's dye, and hydrophobic iodine molecule in solution. The as-prepared I exhibited increased uptake amount in the order of Reichardt's dye > acridine orange hydrochloride > iodine. The largest uptake of the bulky Reichardt's dye by I could be attributed to the optimized structural fitting of Reichardt's dye into the large threedimensional void space of I. The structure of Reichardt's dye-encapsulated I_RD was unambiguously revealed by X-ray crystallography for the first time.
Topologically interesting new In-MOFs were prepared by using a 4,4 0 -biphenyldicarboxylate bridging ligand and In(NO 3 ) 3 $xH 2 O. Two isomeric forms of In-MOFs were independently prepared and characterized by X-ray crystallography, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), elemental analysis, and gas sorption analysis. By simply using different solvents, N,Ndimethylformamide or N,N-diethylformamide, we obtained two new In-MOFs. Despite the same coordination mode of an In III node, these two anionic MOFs adopted distinct crystal structures. One isomer (1) showed an overall 4-fold interpenetrated uninodal 4-connected diamond network with Z t ¼ 1 and Z n ¼ 2 (class IIa). The other (2) showed a 4-fold interpenetrated uninodal 4-connected diamond network with Z t ¼ 2 and Z n ¼ 2 (class IIIa). Thus, despite the same metal-ligand connectivity, 1 and 2 are unusual isomeric MOFs based on the ways of catenation. This may be accounted for by the flexible bonding nature of the In-centered pseudotetrahedral motif in the presence of counter-cations with different dimensions. The In-MOFs 1 and 2 exhibited different counter ion distributions and porosity properties. Interestingly, the In-MOF 1 showed a reversible framework transformation from crystalline form / amorphized form (after activation) / crystalline state (after resolvation). This reversible transformation can also be explained by the flexible bonding nature of the In III ion with four h 2coordinated 4,4 0 -BPDC ligands.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.