No abstract

The appropriate and reliable detection tool for dopamine is still beyond the reach of modern pharmaceutical researchers. To fulfill this concern, herein, we have developed a bio-friendly, aqua-stable boronic acid...

Cu(ii) ions doped into ZIF-8 MOFs are shown to activate C–H bonds in benzylic hydrocarbons to their corresponding alcohol/ketone products.

No abstract

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.

In the present study, an easy and an efficient approach is reported for the acetylation of alcohols, amines, phenols, and thiols under solvent- and catalyst-free conditions. The experimental conditions were milder than conventional methods and the reactions were completed in shorter reaction time. The examined substrates afforded higher yields of the acetylated products under the short reaction time. Comparison of this work with earlier reported procedures reveals that this method offers some advantages than with reported catalysts and solvents. The as-synthesized products were characterized by 1H-NMR and GC-MS techniques to ensure their purity and identity. In addition, a possible mechanism was also proposed for this reaction.

In recent years, one of the analogous metal organic frameworks (MOFs) with UiO‐66(Zr) topology receiving wider attention is UiO‐66(Ce), which exhibits interesting properties and high thermal and chemical stability. Hence, in the present work, UiO‐66(Ce) is synthesized by adopting an earlier procedure and characterized by series of spectroscopic techniques like UV‐visible (UV‐Vis), Fourier transform infrared (FT‐IR), Raman and scanning electron microscope (SEM) to confirm its structural features and crystallinity using powder X‐ray diffraction (XRD) and these results are in close agreement with other reports. The catalytic performance of UiO‐66(Ce) was evaluated in the Friedel–Crafts alkylation reaction between β‐nitrostyrene and indole to obtain heterocyclic compounds with biological activity. A series of control experiments indicate that Ce4+ located within the framework plays an important role in promoting this reaction and its activity is found to be much superior to that of UiO‐66(Zr). This enhanced activity with Ce4+ compared to Zr4+ is attributed due to the higher oxophilicity of Ce4+, which can readily bind with an oxygen‐containing substrate such as β‐nitrostyrene. The leaching test confirms the heterogeneity of the reaction and the catalyst can be reused three times with identical activity to the fresh solid. UiO‐66(Ce) shows wide substrate scope with high yields of the desired product. A proposed mechanism is also discussed.

We developed a porous zirconium (Zr) ions containing diamine fuctionalized metal-organic framework (MOF). The synthesized MOF has similar structure like DUT-52 (DUT = Dresden University of Technology), which has face...