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The poor solubility of the antidiabetic drug gliclazide (Glc) is due to its hydrophobic nature. This research is aimed at improving Glc’s solubility and drug release profile, as well as at investigating additional benefits such as bioactivity and antioxidant activity, by forming binary complexes with HPβCD at different w / w ratios (1 : 1, 1 : 2.5, 1 : 4, and 1 : 9) and ternary complexes with HPβCD and Tryp at 1 : 1 : 1, 1 : 1 : 0.27, 1 : 2.5 : 0.27, 1 : 3.6 : 3.6, 1 : 4 : 1, and 1 : 9 : 1, respectively. Complexes were prepared by the physical mixing (PM) and solvent evaporation (SE) methods. The prepared inclusion complexes were meticulously characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectra. To verify our findings, the inclusion complexes were evaluated by equilibrium solubility, in vitro drug release profile, kinetic models, and antidiabetic and antioxidant activities in animal models. Our results demonstrated that the solubility and drug release profile were found to be enhanced through binary as well as ternary complexes. Notably, ternary complexes with a ratio of 1 : 9 : 1 showed the highest solubility and drug release profile compared to all other preparations. Data on antioxidant activity indicated that the ternary complex had the higher total antioxidant status (TAS), superoxide dismutase (SOD), and catalase (CAT) activity than the binary complex and Glc alone, in contrast to the diabetic group. In vivo antidiabetic activity data revealed a high percentage reduction in the blood glucose level by ternary complexes (49–52%) compared to the binary complexes (45–46%; p ≤ 0.05 ). HPβCD and Tryp provide a new platform for overcoming the challenges associated with poorly soluble Glc by providing greater complexing and solubilizing capabilities and imparting ancillary benefits to improve the drug’s antidiabetic and antioxidant activities.

Novel mono- and dinuclear dimethyltin(IV) complexes were synthesized using tridentate Schiff base ligands, derived from 2-amino-2-hydroxymethyl-propane-1,3-diol and various aldehydes. These diorganotin(IV) compounds displayed good catalytic activity for solvent-free cycloaddition of CO2 to epoxides at ambient pressure. These catalysts efficiently completed the insertion of CO2 to various epoxides at low catalyst loadings (0.1–1.0 mol%) in 1–6 hours giving high values of TONs around 1000. The catalyst further usability for three continuous reaction runs in the reaction mixture gives the same activity revealing the remarkable stability of these compounds under the given reaction conditions. Therefore, organotin(IV) complexes are efficient catalysts for the synthesis of the industrially important cyclic carbonates from epoxides at ambient pressure under solvent-free conditions.

Drugs are the moieties used in treating diseases. Drugs include vaccines, antidepressants, antibiotics, antiviral, anesthetics, stimulants, and inhibitors. Drugs perform functions in the living system and are associated with the change in body metabolism. Various mechanisms are linked to drug distribution and drug action. Mechanisms are specific and they target specific region or process in the body. Mechanisms for antibiotic resistance include modification of bacterial proteins which are the targets of antibiotics, enzymatic modification of antibiotics, reduction in drug uptake, efflux pump modification, plasmid modification, and inhibition of metabolic pathways. Drugs are used individually or in combinations to maximize each other’s effect and minimize the risk. Factors defining drugs efficiency include nature of disease, medical history, drug dosage, treatment time, age, and environmental factors. Drug resistance is the ineffectiveness of drug against a disease after specific period. Factors associated with drug resistance are the excessive or inappropriate use of drugs and the modification in target sites including genetic mutations. Genetic mutations lead to therapeutic and economic problems as new therapies and drug combinations require time and resources. Some pathogens are resistant to multiple drugs known as multi-drug resistance. Drugs designing by considering these challenges can minimize the drug resistance.

In recent decades, electrochemical water splitting has caught researcher’s attention for cost effective and green way to meet world’s energy requirement. In present work, rod structured hierarchical cerium oxide/C derived from metal organic framework (MOF) electrocatalyst was synthesized via hydrothermal route directly grown on nickel foam (NF) for oxygen evolution reaction (OER) in 1 M KOH solution. The fabricated electrocatalysts were characterized via different analytical techniques to analyze the morphology, crystallinity and oxidation states. The electrochemical performances of the synthesized materials were investigated exhibiting outstanding OER performances, with low over potential of 297 mV to achieve a current density of 10 mA/cm2. The electrocatalyst also attains low Tafel slope (46 mV/dec) provides the way of electron transfer with long term stability (1000 cyclic voltammetry cycles and 15 h) chronoamperometry. These all results suggest that cerium oxide derived from MOF could be used as substitution for noble metal catalysts to develop promising, new and active electrocatalyst.

Ytterbium (Yb) doped NiCr 0.1 Yb x Fe 1.9−x O 4 (x = 0.00, 0.002, 0.04, 0.06, 0.08) spinel ferrites with different crystallite sizes have been prepared by co-precipitation technique and their magnetic and dielectric properties were investigated. X-ray diffraction data suggested that, after doping, all the samples possess a main spinel phase along with few traces of YbFeO 3 (secondary phase). The addition of Yb 3+ resulted in a decrease of crystallite size and an increase in X-ray density. The magnetic measurements indicated that saturation magnetization (M s ), coercivity (H c ) and remanence (M r ) of all the samples decreased by increasing dopant (Yb) concentration. Dielectric constant, dielectric loss and tan loss were also minimized with the increase in frequency as well as increase in the concentration of Yb 3+ ions in the nickel chromium based spinel ferrites. AC conductivity was directly proportional to frequency and inversely proportional to concentration of Yb 3+ ions. These ytterbium doped nickel ferrites may be potential candidates for the fabrication and development of high frequency switching devices.

Synthesis of 2D MOFs is often sensitive to the reaction conditions like temperature and solvent etc. Cu(II)-5-azidoisophthalate MOF (Cu(II)–5N3IP) has been synthesized at room temperature as well as under solvothermal conditions. The azide functional group remained stable during solvothermal synthesis at 85 °C. Cu(II)–5N3IP crystallized in a Kagome-type structure. Typical Cu2 paddle-wheels are connected to each other by 5N3IP ligands in infinite 2D sheets in the (001) plane, featuring 1D infinite channels within each layer. This MOF is used for the adsorption of methylene blue (MB), rhodamine B (RhB), methyl orange (MO), and Congo red (CR). The adsorption is selective to the dimensions, shapes and ionic strengths of the dyes. Cu(II)–5N3IP exhibited adsorption rates in the order MB > CR > RhB > MO. Cu(II)–5N3IP is used as a catalyst for aerobic oxidation and Knoevenagel condensation. 3–10 mol% of Cu–5N3IP selectively catalyzes the oxidation of benzyl alcohol to benzaldehyde in 9–20 h at 60 °C. In Knoevenagel condensation, the reaction of both unsubstituted and substituted benzaldehydes at room temperature was observed at a very low catalyst loading of 3 mol% of MOF within a short time of 3–60 min. This 2D MOF has proved to be more efficient for dye adsorption and the catalytic applications under investigation (such as alcohol oxidation and Knoevenagel condensation) than its analogous 3D or 0D materials.

A series of novel N′-arylmethylidene-3-methyl-1-phenyl-6-p-chlorophenyl-1H-pyrazolo[3,4-b]pyridine-4-carbohydrazide (2a–2t) has been synthesized from hydrazide (1). The structures of newly synthesized compounds were confirmed by FT-IR, EI-MS, 1H NMR and 13C NMR techniques. The title compounds were evaluated for antioxidant and antiplatelet aggregation effect induced by arachidonic acid (AA) and collagen. All the compounds have exhibited high antioxidant potential and antiplatelet activity but (2c, 2e, 2f, 2g, 2i, 2m, 2o and 2q) have revealed superlative antiplatelet activity. The molecular docking against cyclooxygenase-1 and 2 (COX-1 and COX-2) and quantitative structure-activity relationship (QSAR) were performed in describing their antiplatelet potential against AA and collagen along with antioxidant potential determined by ABTS, DPPH and iron chelating methods. The molecular docking study exhibited that compounds (2c, 2e, 2f, 2g, 2i, 2l, 2m, 2o and 2q) were found to be active against COX-1 while 2o compound also showed activity against COX-2. Compounds 2g and 2l were found to have higher energy stabilization values in comparison to Aspirin. Computational evaluations both molecular docking and QSAR are in good agreement with antiplatelet and antioxidant activities of the compounds (2a–2t). All the compounds especially 2g, 2l, 2m might be promising antiplatelet agents and might be helpful in the synthesis of new drugs for the treatment of cardiovascular and anti-inflammatory diseases.

Methacrylamide-acrylic acid-N-isopropylacrylamide terpolymeric hydrogels have been prepared via free radical polymerization using diammonium-peroxo-disulphate initiator system and ethylene glycol-di-methacrylate as a cross-linker. The hydrogels were characterized by Fourier transform infrared spectroscopy, field emission scanning electron microscopy, thermogravimetric analysis, and differential scanning calorimetry. Molar mass was determined by viscometric method. Rheological profiling of the hydrogels was carried out by rheological measurements at various temperatures and methacrylamide contents in hydrogels. Thermogravimetric data were analyzed to assess the kinetic triplet by iso-conversional method. The values of apparent activation energy (E a) figured out from TG data were measured for each step by Kissinger–Akahira–Sunose method. On the findings of results, the decomposition reaction of terpolymeric hydrogels has been analyzed as a slow reaction, which is evident from the low-frequency factor values (A), i.e., 3 × 106, 2 × 1010, and 4 × 1015 s−1, respectively. The master plot method was used to predict the mechanism for degradation of MANIPAM-7. Flow curve and frequency sweep tests at different temperatures showed temperature dependency with shear rate indicating the pseudo-plastic nature of the synthesized samples. The rheological parameters were analyzed using various models. Out of these methods, the Ostwald, modified Bingham, and Herschel–Bulkley models were established to provide better fit to experimental data. Dynamic moduli measured as a function of angular frequency showed viscoelastic nature of all the samples. Frequency sweep studies indicated that storage (G′) and loss modulus (G″) showed an increase with increasing concentration of methacrylamide. Composition dependency of crossover frequency directed an increase in relaxation time with methacrylamide contents in the hydrogel.

Europium (Eu) doped spinel cobalt ferrites having composition CoEuxFe2−xO4 where x = 0.00, 0.03, 0.06, 0.09, 0.12 were fabricated by co-precipitation route. In order to observe the phase development of the ferrite samples, thermo-gravimetric analysis was carried out. The synthesized samples were subjected to X-ray diffraction analysis for structural investigation. All the samples were found to constitute face centered cubic (FCC) spinel structure belonging to Fd3m space group. Scanning electron microscopy revealed the formation of nanocrystalline grains with spherical shape. Energy dispersive X-ray spectra confirmed the presence of Co, Eu, Fe and O elements with no existence of any impurity. The magnetic hysteresis curves measured at room temperature exhibited ferrimagnetic behavior with maximum saturation magnetization (Ms) of 65 emu/g and coercivity (Hc) of 966 Oe. The origin of ferrimagnetism in Eu doped cobalt ferrites was discussed in detail with reverence to the allocation of Co2+ and Fe3+ ions within the spinel lattice. The overall coercivity was increased (944–966 Oe) and magnetization was decreased (65–46 emu/g) with the substitution of Eu3+. The enhancement of former is ascribed to the transition from multi domain to single domain state and reduction in lateral is attributed to the incorporation of nonmagnetic Eu ions for Fe, resulting in weak superexchange interactions. Keywords: Europium doped cobalt ferrites, Co-precipitation, X-ray diffraction, Scanning electron microscopy, Magnetic properties

Craving to search sources of energy is constantly compelling the mankind to find a source that is renewable or has enormous reservoirs and at the same time it poses no hazardous effect to mankind. Today’s energy deficient world has been seeking for an electrocatalyst which has a simple and facile synthesis strategy with marvellous catalytic performance and has outstandingly sustained stability for the highly lethargic Oxygen Evolution Reaction (OER). Here, a Ni-based mixed linker Metal Organic Framework (MOF) was synthesized using 1,3,5-benzenetricarboxylic acid (BTC) and 4,4`-bipyridine (bpy) as organic linkers. Carbon Dots (CDs) were incorporated into MOF during synthesis to impart synergistic effect to the as-synthesized composite. All the synthesized samples i.e CDs, MOF and CDs@MOF were characterized by various techniques to confirm the structural, compositional, morphological and textural analysis. The synthesized composite possessed rods like morphology with uniform distribution of CDs which offered superb stability for almost 40 hrs, large electrochemical active surface area (ECSA), least charge transfer resistance (Rct), high turnover frequency (TOF), reasonably low onset potential, low overpotential and a comparably low Tafel slope. The electrocatalyst owed its great catalytic efficiency and substantial stability due to the synergistic effect between CDs and MOF. This work is an effort to exploit the fabulous potential of MOF based nano-composite towards water splitting.

Dy–Ni substituted Mn1-xNixFe2-yDyyO4 (x = 0.0–0.1 and y = 0.0–0.2) soft magnetic oxides were synthesized using a size controlled micro-emulsion method. X-ray diffraction (XRD) analysis was employed to confirm the spinel structure of synthesized ferrites. Crystallite size was found to decrease (33-22 nm) while lattice constant was increased (8.58–8.63 A) by increasing dopants content. FTIR bands observed in the range 500–600 cm−1 is the evidence to form the spinel structure of these ferrites. Dielectric constant (e′) and dielectric loss (e") were observed to decrease with the increase of frequency due to hopping mechanism. Hysteresis curves exhibited soft nature of synthesized nanoferrites. Remanence (MR) and saturation magnetization (MS) were increased with the incorporation of Dy and Ni ions. The decreased in dielectric losses and increased in magnetic parameters suggested that these ferrites are potential candidates for magnetic recording heads.

A series of nanostructured ferrites having chemical composition Mg0.7Co0.3YbxFe2−xO4 (x=0.0–0.08) was prepared by the chemical co-precipitation route. The synthesized samples were characterized by X-ray diffraction (XRD), Thermo-gravimetric analysis (TGA), differential thermal analysis (DTA), vibrating sample magnetometer (VSM) and impedance analyzer. The analysis of XRD patterns confirmed the spinel structure and the crystallite size calculated by Scherer's formula was found in the range of 18–43 nm. The crystallite size was small enough to obtain considerable signal to noise ratio in the recording media. The lattice constant was increased from 8.362 Ǻ to 8.383 Ǻ as the Yb contents were increased in the magnesium-cobalt ferrites. The TGA and DTA were carried out for prepared sample to investigate the thermal decomposition process. Magnetization results obtained from VSM measurements elucidate that the substitution of rare earth ytterbium decreased the saturation magnetization and retentivity. The dielectric properties of the samples were studied at room temperature in the frequency range of 1 MHz to 3 GHz and the samples exhibited the dispersion in high frequency region. The dielectric constant (e) and dielectric loss (tan δ) were decreased with the increased frequency and ytterbium doping. The dielectric parameters were explained on the basis of space charge distribution. The dielectric and magnetic parameters suggested that these nano-materials are potential candidates for switching and recording media applications.

SummaryThe coordination networking of discrete metal-organic polyhedra (MOPs) involving different ligands as well as metals is a challenging task due to the features of limited solubility and chemical stability of these polyhedra. An unusual approach, ligand-oriented polyhedral networking via click chemistry and further metal coordination is reported here. An alkyne decorated Cu(II)-MOP self-catalyzes the regioselective click reaction (1,3-dipolar cycloaddition) using azide-functionalized ligands under unconventional reaction conditions. Introducing new metal ions, M(II), interlinks the carboxylic groups on the MOP surfaces creating coordination networks. On the other hand, exposure of the respective individual ligand components in the presence of Cu(II) promotes an in-situ click reaction along with metal coordination generating a new 3D-framework. These materials demonstrated a high drug hosting potential exhibiting a controlled progressive release of anticancer (5-flourouracil) and stimulant (caffeine) drugs in physiological saline at 37 °C. These innovative and unconventional MOP networks provide a significant conceptual advance in understanding.

Ca–Ni co-substituted samples of nanocrystalline spinel ferrites with chemical formula Mg 1− x Ca x Ni y Fe 2− y O 4 ( x =0.0–0.6, y =0.0–1.2) were synthesized by the micro-emulsion method and were annealed at 700 °C for 7 h. The synthesized samples were characterized by x-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, vibrating sample magnetometry (VSM) and dielectric measurements. The XRD and FTIR analysis reveals that single phase samples can be achieved by substituting Ca and Ni ions at Mg and Fe sites respectively in cubic spinel nano-ferrites. The crystallite size of the synthesized samples was found in the range 29–45 nm. The saturation magnetization ( M s ) increases from 9.84 to 24.99 emu/g up to x =0.2, y =0.4 and then decreases, while the coercivity ( H c ) increases continuously from 94 to 153 Oe with the increase in dopants concentration. The dielectric properties of these nano materials were also studied at room temperature in the frequency range 100 MHz to 3 GHz. The dielectric parameters were found to decrease with the increased Ca–Ni concentration. Further the peaking behavior was observed beyond 1.5 GHz. The frequency dependent dielectric properties of all the samples have been explained qualitatively on the basis of the Maxwell–Wagner two-layer model according to Koop's phenomenological theory. The enhanced magnetic parameters and reduced dielectric properties make the synthesized materials suitable for switching and high frequency applications, respectively.

Magnesium ferrite (MgFe2O4) nano-structures doped with Ni–Co at magnesium and iron sites respectively were fabricated by the micro-emulsion method and characterized by the X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM) and dielectric measurements. The analysis of XRD patterns confirm the single phase spinel structure and the crystallite size calculated by Scherer’s formula lies in the range of 15–26 nm. The spectral studies elucidate the characteristic feature of spinel phase. The real and imaginary parts of dielectric constant and dielectric loss exhibit peaking behavior. The dielectric properties have been explained on the basis of Debye-type relaxation phenomenon in accordance with Koop’s phenomenological theory. The increase in the tendency of saturation magnetization is consistent with the enhancement of crystallinity. The crystallite size is small enough to obtain considerable signal to noise ratio in the recording media. The optimized dielectric and magnetic parameters suggest that the material with composition Mg0.6 Ni0.4 Co0.4 Fe1.6O4 may be used for applications in recording media and microwave devices.

Water splitting is the key step towards artificial photosystems for solar energy conversion and storage in the form of chemical bonding. The oxidation of water is the bottle-neck of this process that hampers its practical utility; hence, efficient, robust, and easy to make catalytic systems based on cheap and earth-abundant materials are of exceptional importance. Herein, an in situ generated cobalt catalyst, [Co-II(TCA)(2)(H2O)(2)] (TCA=1-mesityl-1,2,3-1H-triazole-4-carboxylate), that efficiently conducts photochemical water oxidation under near-neutral conditions is presented. The catalyst showed high stability under photolytic conditions for more than 3 h of photoirradiation. During electrochemical water oxidation, the catalytic system assembled a catalyst film, which proved not to be cobalt oxide/hydroxide as normally expected, but instead, and for the first time, generated a molecular cobalt complex that incorporated the organic ligand bound to cobalt ions. The catalyst film exhibited a low overpotential for electrocatalytic water oxidation (360 mV) and high oxygen evolution peak current densities of 9 and 2.7 mA cm(-2) on glassy carbon and indium-doped tin oxide electrodes, respectively, at only 1.49 and 1.39 V ( versus a normal hydrogen electrode), respectively, under neutral conditions. This finding, exemplified on the in situ generated cobalt complex, might be applicable to other molecular systems and suggests that the formation of a catalytic film in electrochemical water oxidation experiments is not always an indication of catalyst decomposition and the formation of nanoparticles.