Small aliphatic alcohols are excellent fuels that have a much higher energy density than liquid H2. It is advantageous to avoid their complete oxidation to CO2 and produce chemicals with...

A zirconium (Zr) metal–organic framework having a DUT-52 (DUT stands for Dresden University of Technology) structure with face-centered cubic topology and bearing the rigid 1-(2,2,2-trifluoroacetamido) naphthalene-3,7-dicarboxylic acid (H2NDC-NHCOCF3) ligand was prepared, and its solid structure was characterized with the help of the X-ray powder diffraction (XRPD) technique. Other characterization methods like thermogravimetric analysis (TGA) and Fourier transform infrared (FT-IR) spectroscopy were applied to verify the phase purity of the compound. In order to get the solvent-free compound (1′), 1 was stirred with methanol for overnight and subsequently heated at 100 °C overnight under vacuum. As-synthesized (1) and activated (1′) compounds are thermally stable up to 300 °C. The Brunsuer Emmett-Teller (BET) surface area of 1′ was found to be 1105 m2 g–1. Fluorescence titration experiments showed that 1′ exhibits highly selective and sensitive fluorescence turn-on behavior toward cyanide (CN–) anion. The interference experiments suggested that other anions did not interfere in the detection of CN–. Moreover, a very short response time (2 min) was shown by probe 1′ for CN– detection. The detection limit was found to be 0.23 μM. 1′ can also be effectively used for CN– detection in real water samples. The mechanism for the selective detection of CN– was investigated systematically. Furthermore, the aerobic oxidation of cyclohexane was performed with 1′ under mild reaction conditions, observing higher activity than the analogous DUT-52 solid under identical conditions. These experiments clearly indicate the benefits of hydrophobic cavities of 1′ in achieving higher conversion of cyclohexane and cyclohexanol/cyclohexanone selectivity. Catalyst stability was proved by two consecutive reuses and comparing the structural integrity of 1′ before and after reuses by the XRPD study.

The formation of small 1 to 3 nm organicligand free metal-oxide nanocrystals (NCs) is essential to utilization of their attractive size-dependent properties in electronic devices and catalysis. We now report that hexaniobate cluster-anions, [Nb 6 O 19 ] 8À , can arrest the growth of metal-oxide NCs and stabilize them as water-soluble complexes. This is exemplified by formation of hexaniobate-complexed 2.4-nm monoclinic-phase CuO NCs (1), whose ca. 350 Cu-atom cores feature quantum-confinement effects that impart an unprecedented ability to catalyze visible-light water oxidation with no added photosensitizers or applied potentials, and at rates exceeding those of hematite NCs. The findings point to polyoxoniobate-ligand entrapment as a potentially general method for harnessing the sizedependent properties of very small semiconductor NCs as the cores of versatile, entirely-inorganic complexes.

The formation of small 1 to 3 nm organic‐ligand free metal‐oxide nanocrystals (NCs) is essential to utilization of their attractive size‐dependent properties in electronic devices and catalysis. We now report that hexaniobate cluster‐anions, [Nb6O19]8−, can arrest the growth of metal‐oxide NCs and stabilize them as water‐soluble complexes. This is exemplified by formation of hexaniobate‐complexed 2.4‐nm monoclinic‐phase CuO NCs (1), whose ca. 350 Cu‐atom cores feature quantum‐confinement effects that impart an unprecedented ability to catalyze visible‐light water oxidation with no added photosensitizers or applied potentials, and at rates exceeding those of hematite NCs. The findings point to polyoxoniobate‐ligand entrapment as a potentially general method for harnessing the size‐dependent properties of very small semiconductor NCs as the cores of versatile, entirely‐inorganic complexes.