Carbon dioxide (CO2) fixation to generate chemicals and fuels is of high current importance, especially toward finding mild and efficient strategies for catalytic CO2 transformation to value added products. Herein, we report a novel Lewis acid–base bifunctional amine-functionalized dysprosium(III) metal–organic framework [Dy3(data)3·2DMF]·DMF (2,5-data: 2,5-diamino-terephthalate), NH2-TMU-73. This compound was fully characterized and its crystal structure reveals a 3D metal–organic framework (MOF) with micropores and free NH2 groups capable of promoting the chemical fixation of CO2 to cyclic carbonates. NH2-TMU-73 is built from the Dy(III) centers and data2– blocks, which are arranged into an intricate underlying net with a rare type of xah topology. After activation, NH2-TMU-73 and its terephthalate-based analogue (TMU-73) were applied for CO2-to-epoxide coupling reactions to produce cyclic carbonates. Important features of this catalytic process concern high efficiency and activity in the absence of cocatalyst, use of solvent-free medium, atmospheric CO2 pressure, and ambient temperature conditions. Also, NH2-TMU-73 features high structural stability and can be recycled and reused in subsequent catalytic tests. An important role of free amino groups and open metal sites in the MOF catalyst was highlighted when suggesting a possible reaction mechanism.
In this work, a bio-metal–organic framework (Bio-MOF) coated with a monodispersed layer of chitosan (CS; CS/Bio-MOF) was synthesized and applied as a pH-responsive and target-selective system for delivery of doxorubicin (DOX) in the treatment of breast cancer. The efficiency of the nanocarrier in loading and releasing DOX was assessed at different pH levels. To monitor the in vitro drug release behavior of the drug-loaded carrier, the carrier was immersed in a phosphate buffered saline solution (PBS, pH 7.4) at 37 °C. According to the observations, the nanocarrier presents a slow and continuous release profile as well as a noticeable drug loading capacity. In addition, the carrier demonstrates a pH-responsive and target-selective behavior by releasing a high amount of DOX at pH 6.8, which is indicative of tumor cells and inflamed tissues and releasing a substantially lower amount of DOX at higher pH values. In addition, the results indicated that pH is effective on DOX uptake by CS/Bio-MOF. A 3.6 mg amount of DOX was loaded into 10 mg of CS/Bio-MOF, resulting in a 21.7% removal at pH 7.4 and 93.0% at pH 6.8. The collapsing and swelling of the CS layers coated on the surface of the Bio-MOFs were found to be responsible for the observed pH dependence of DOX delivery. Moreover, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and the trypan blue test were performed on the MCF-7 (breast cancer) cell line in the presence of the CS/Bio-MOF carrier to confirm its biological compatibility. In addition, Annexin V staining was conducted to evaluate the cytotoxicity of the free and loaded DOX molecules. On the basis of the obtained optical microscopy, MTT assay, fluorescence microscopy, and dyeing results, the CS/Bio-MOF carrier greatly enhances cellular uptake of the drug by the MCF-7 cells and, therefore, apoptosis of the cells due to its biocompatibility and pH-responsive behavior.
This study proposes an approach for improving catalysis of oxidative desulfurization (ODS) of diesel fuel under mild reaction conditions and enhancing supercapacitor (SC) properties for storage of a high amount of charge. Our approach takes advantage of a novel dual-purpose cobalt(II)-based metal–organic framework (MOF), [Co(2-ATA)2(4-bpdb)4] n (2-ATA: 2-aminoterephthalic acid and 4-bpdb: N,N-bis-pyridin-4-ylmethylene-hydrazine as the pillar spacer), which is called NH2-TMU-53. Due to the stability of the used compound, we decided to evaluate the capability of this compound as a novel electrode material for storing energy in supercapacitors, and also to investigate its catalytic capabilities. It is demonstrated that the addition of H2O2 as an oxidant enhances the efficiency of sulfur removal, which indicates that NH2-TMU-53 can efficiently catalyze the ODS reaction. According to the kinetics results, the catalyzed process follows pseudo-first-order kinetics and exhibits 15.57 kJ mol–1 activation energy. Moreover, with respect to the radical scavenging evaluations, the process is governed by direct catalytic oxidation rather than indirect oxidative attack of radicals. Furthermore, NH2-TMU-53 was applied as an electrode material for energy storage in SCs. This material is used in the three-electrode system and shows a specific capacitance of 325 F g–1 at 5 A g–1 current density. The asymmetric supercapacitor of NH2-TMU-53//activated carbon evaluates the further electrochemical activity in real applications, delivers the high power density (2.31 kW kg–1), high energy density (50.30 Wh kg–1), and long cycle life after 6000 cycles (90.7%). Also, the asymmetric supercapacitor practical application was demonstrated by a glowing red light-emitting diode and driving a mini-rotating motor. These results demonstrate that the fabricated device presents a good capacity for energy storage without pyrolyzing the MOF structures. These findings can guide the development of high-performance SCs toward a new direction to improve their practical applications and motivate application of MOFs without pyrolysis or calcination.
A new metal−organic framework (MOF), [Zn 4 (μ 4 -O)(μ 6 -L) 2 (H 2 O) 2 ] n • nDMF (ZSTU-10), was assembled from zinc(II) nitrate and N,N′,N″-bis(4carboxylate)trimesicamide linkers and fully characterized. Its crystal structure discloses an intricate two-fold 3D+3D interpenetrated MOF driven by the [Zn 4 (μ 4 -O)]-based tetragonal secondary building units and the C3-symmetric tris-amide-tricarboxylate linkers (μ 6 -L 3− ). Topological analysis of ZSTU-10 reveals two interpenetrated 3,6connected nets with an rtl (rutile) topology. Z-Scan analysis at 532 nm was conducted to study a nonlinear optical (NLO) behavior of ZSTU-10. The nonlinear responses of ZSTU-10 were explored under various laser intensities, revealing notable third-order NLO properties in the visible region. A large two-photon absorption at lower incident intensities highlights the fact that ZSTU-10 can be applied in optical limiting devices as well as optical modulators. Moreover, a nonlinear refractive index (n 2 ) is indicative of a self-defocusing behavior. This work thus expands a family of novel MOF materials with remarkable optical properties.
2-(2-Hydroxyethylamino)ethylamino)cyclohexanol (HEAC) and copper and zinc complexes, [Cu(HEAC) Cl]Cl (1), [Cu(HEAC)Br]Br (2), [Zn(HEAC)Cl 2 ] (3), were prepared and identified by elemental analysis, FT-IR, UV-Vis, 1 H NMR spectroscopy and single-crystal X-ray diffraction. Also nanoparticles of 1-3 were prepared for anticancer studies by ultrasonic irradiation. Particle size and morphology of the nano particles are investigated by PXRD and SEM, respectively. X-ray analysis revealed that the ionic complexes 1 and 2 are isostructural. In the structure of complexes 1 and 2, the metal atom has a CuN 2 O 2 X (X: Cl (1), Br (2)) environment with square-pyramidal geometry, containing the tetradentate N 2 O 2 -donor HEAC. The bond length of the axial position in the square-pyramidal geometry of 1 and 2 is elongated. Complex 3 has a ZnN 2 OCl 2 environment with trigonal bipyramidal geometry around the zinc atom in which the HEAC acts as mer-N 2 O-donor. The ability of HEAC and nano particles 1-3 to interact with the nine biomacromolecules (BRAF kinase, CatB, DNA gyrase, HDAC7, rHA, RNR, TrxR, TS and Top II) are investigated by docking calculations. For examination of the docking results, the in vitro activities of four compounds against the human leukemia cell line K562 were investigated by evaluation of IC 50 values and mode of cell death (apoptosis). The thermodynamic stability of the compounds along with the charge distribution pattern were studied by DFT and NBO analysis, respectively.
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