Synthesis, Crystal Structures and Molecular Packing of a Series of Pyrazolo-Benzothiazine Hybrid Derivatives

Abstract  

The crystal structures of four derivatives of pyrazolo[4,3-c][1,2]benzothiazine-2,4-dihydro-3,4-dimethyl-,5,5-dioxide containing benzothiazine dioxide and pyrazolo fused rings that have been synthesized were determined. (C₁₁ H₁₁ N₃ O₂ S): Mr = 249.29, monoclinic, P2₁/c, a = 8.3070(3), b = 13.6331(5), c = 10.1661(3) ?, β = 106.924(2)°, V = 1101.45(7) ?^3, Z = 4. (C₁₂ H₁₃ N₃ O₂ S): Mr = 263.31, monoclinic, P2₁/n, a = 9.729(3), b = 11.224(4), c = 11.436(3) ?, β = 98.85(2)°, V = 1233.9(7) ?³, Z = 4. (C₁₄ H₁₅ N₃ O₄ S): Mr = 321.35, monoclinic, P2₁/c, a = 9.2534(3), b = 19.3920(7), c = 7.9489(2) ?, β = 95.323(2)°, V = 1420.21(8) ?^3, Z = 4. (C₁₄ H₁₅ N₃ O₃ S): Mr = 305.35, monoclinic, P2₁ /c, a = 13.816(7), b = 7.464(3), c = 14.674(8) ?, β = 109.05(3)°, V = 1430.3(12) ?³, Z = 4. The heterocyclic thiazine rings adopt half-chair conformations, and the mean-planes of the phenyl and pyrazolo rings lie between 10.43(11) and 15.93(16)° with respect to each other. In each case, the geometry about thiazine N-atom is trigonal pyramidal and only the first compound containing a donor N-atom shows classical hydrogen bonds. However, non-classical H-bonding of the type C–H···O is observed in all structures.     

Phytochemical analysis and Enzyme Inhibition Assay of Aerva javanica for Ulcer

Background

Nickel ferrite, a kind of soft magnetic materials is one of the most attracting class of materials due to its interesting and important properties and has many technical applications, such as in catalysis, sensors and so on. In this paper the synthesis of NiFe₂O₄ nanoparticles by the hydrothermal method is reported and the inhibition of surfactant (Glycerol or Sodium dodecyl sulfate) on the particles growth is investigated.

Methods

For investigation of the inhibition effect of surfactant on NiFe₂O₄ particles growth, the samples were prepared in presence of Glycerol and Sodium dodecyl sulfate. The X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM) and inductively coupled plasma atomic emission spectrometer (ICP-AES) techniques were used to characterize the samples.

Results

The results of XRD and ICP-AES show that the products were pure NiFe₂O₄ and also nanoparticles grow with increasing the temperature, while surfactant prevents the particle growth under the same condition. The average particle size was determined from the Scherrer's equation and TEM micrographs and found to be in the range of 50-60 nm that decreased up to 10-15 nm in presence of surfactant. The FT-IR results show two absorption bands near to 603 and 490 cm^-1 for the tetrahedral and octahedral sites respectively. Furthermore, the saturated magnetization and coercivity of NiFe₂O₄ nanoparticles were in the range of 39.60 emu/g and 15.67 Q_e that decreased for samples prepared in presence of surfactant. As well as, the nanoparticles exhibited a superparamagnetic behavior at room temperature.

Conclusions

Nanosized nickel ferrite particles were synthesized with and without surfactant assisted hydrothermal methods. The results show that with increasing of temperature, the crystallinity of nanoparticles is increased. In the presence of surfactants, the crystallinity of NiFe₂O₄ nanoparticles decreased in comparison with surfactant- free prepared samples. All of the nickel ferrite nanoparticles were superparamagnetic at room temperature.

Graphical abstract

     

Potential energy surfaces for rearrangements of Berson trimethylenemethanes

In this research, thermal rearrangements of the Berson trimethylenemethanes (Berson-TMMs) have been investigated by employing density functional theory (DFT) and high-level ab initio methods, such as the complete active space self-consistent field (CASSCF), multireference second-order M?ller-Plesset perturbation theory (MRMP2), multireference configuration interaction singles and doubles (MRCISD), and coupled-cluster singles and doubles with perturbative triples [CCSD(T)]. In all computations Pople's polarized triple-ζ split valence basis set, 6-311G(d,p), is utilized. The relevant portions of the lowest-energy, singlet-spin potential energy surface of the C(4)H(6) (parent TMM), C(6)H(8) (Berson-TMMa), and C(8)H(12) (Berson-TMMc) chemical systems have been explored in order to determine the reaction energies and activation parameters accurately, with the ultimate objective of providing a theoretical account of experiments by Berson on TMMc. The nature of the orthogonal and the planar structures of the parent TMM have been clarified in this study. We have concluded that the orthogonal TMM (1)B(1) minimum has a C(2v) symmetry structure, and there is no pyramidalization in the unique methylene group. It lies at 13.9 kcal mol(-1) above the triplet minimum (3)B(2) at MRCISD level. The closed-shell (1)A(1) state of the planar TMM is not a true minimum but a transition structure (TS) for 180° rotation of the unique methylene group in the orthogonal TMM minimum. It lies at 3.0 kcal mol(-1) above (1)B(1). The planar structures are also involved in the interchange of equivalent orthogonal TMMs (o(1), o(2), o(3)). Many features of the parent TMM are retained in TMMa and TMMc, despite the constraints imposed by the five-membered ring in the latter species. Thus, ring closure to the bicyclic molecules 3a (3c) and 5a (5c) takes place similarly to that in the parent TMM. Likewise, planar TMMa (TMMc) structures are TSs, while orthogonal ones are true minima. The adiabatic singlet-triplet gaps are also similar, being 14.7 (13.0) and 16.5 (16.2) kcal mol(-1) in the orthogonal (o(1)) and planar TMMa (TMMc), respectively. It has been shown here that the substantial reductions in the ring-opening barriers of MCP derivatives 3a (3c) and 5a (5c) can be largely attributed to ring strain in the former and π-bond strain in the latter species.     

Adsorption behavior of iron phthalocyanine at the initial stage on Cu(100) surface

The adsorption behavior of iron phthalocyanine (FePc) on the Cu(100) surface at the initial stage has been investigated by combining scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. At low coverage, FePc molecules deposited on the sample surface at room temperature tend to adsorb dispersedly with their molecular planes parallel to the crystallographic directions of the substrate. Another interesting STM observation for the sub-monolayer coverage is that the molecular axes of FePc are aligned along [037] (as well as $\left[0\overline{3}7\right]$) azimuth. At the monolayer coverage and elevated temperature, two types of ordered structures are observed. The FePc adsorption sites for the experimentally observed two distinct ordered domains have been revealed through DFT calculations. With further increasing the coverage, molecular clusters are formed particularly near the step edges.     

Mineralogical, geochemical and radiological characterisation of Selmo Formation in Batman area, Turkey

This work deals with the mineralogical, geochemical and radiological characterisations of Selmo Formation in Batman neighbourhood. The upper Miocene-Pliocene Selmo Formation is common in the centre of Batman and composed of carbonated sandy claystones and silty-sandy stone lenses. The common whole minerals of the samples are quartz, feldspars, calcite and dolomite. The clay minerals are smectite, illite, chlorite and mixed-layer clay (chlorite-smectite). The geochemical mean values of the samples are 51.7% SiO(2); 12.6% Al(2)O(3); 6.2% Fe(2)O(3); 3.6% MgO; 6.3% CaO; 1.1% Na(2)O; 1.7% K(2)O; 0.8% TiO(2); 0.2% P(2)O(5); 0.1% MnO; and 0.03% Cr(2)O(3). In addition, baseline maps for the concentrations of each radionuclide, the radium equivalent activity and the outdoor gamma dose rate distributions have been plotted for the study area. The mean activity concentrations of (226)Ra, (232)Th, (40)K and (137)Cs were determined to be 32, 24, 210 and 9?Bq?kg(-1), respectively. The assessments of the radiological hazard indices, such as radium equivalent activity, absorbed dose rate in air, annual effective dose equivalent, excess lifetime cancer risk, external hazard index and internal hazard index, were calculated and compared with the internationally accepted reference values. This study shows that the concentrations of radioactivities in the measured samples were within the recommended safety limits and did not pose to be any significant source of radiation hazard.     

Small signal gain and loss measurement of a CW Nd:YAG laser using an antiresonant ring interferometer

An antiresonant ring (ARR) interferometer configuration is introduced for the characterization of a continuous wave (CW) Nd:YAG laser output. The output of the ARR device is precisely characterized todetermine the gain and loss of a laboratory CW Nd:YAG laser by using the Findlay-Clay approach. TheARR arm is then experimentally arranged inside the cavity of an arranged high power side-pumped CWNd:YAG laser. A coated beam splitter with 50–50% reflectivity at normal incidence is placed inside thecavity to provide a wide range of reflectivity from 0 to 100%. This is performed by a rotatable stage and tilting the beam splitter by 10°with the steps of 0.05. By changing the input electrical power of the laser pump the variation of the output laser power is monitored for 20 individual reflectivity of ARR arm.Average pump threshold power of about 180 W is obtained. With the help of the derived equations and obtained threshold power, small signal gain and loss associated with the emerging beam is estimated. It is verified that the former is very dependent to the input parameters. Laser efficiency is also measures 5.6% which is quite comparable with the reported values.     

Minimal and Pseudo-Umbilical Rotational Surfaces in Euclidean Space {\mathbb{E}^4}

In this paper we study general rotational surfaces in ${\mathbb{E}^4}$ whose meridian curves lie in two-dimensional planes. We firstly find all minimal general rotational surfaces by solving the differential equation that characterizes minimal general rotational surfaces. Then we determine all pseudo-umbilical general rotational surfaces in ${\mathbb{E}^4}$ .     

An integral operational matrix based on Jacobi polynomials for solving fractional-order differential equations

This paper aims to construct a general formulation for the Jacobi operational matrix of fractional integral operator. Fractional calculus has been used to model physical and engineering processes that are found to be best described by fractional differential equations. Therefore, a reliable and efficient technique for the solution of them is too important. For the concept of fractional derivative we will adopt Caputo’s definition by using Riemann–Liouville fractional integral operator. Our main aim is to generalize the Jacobi integral operational matrix to the fractional calculus. These matrices together with the Tau method are then utilized to reduce the solution of this problem to the solution of a system of algebraic equations. The method is applied to solve linear and nonlinear fractional differential equations. Illustrative examples are included to demonstrate the validity and applicability of the presented technique.     

Robust optimal dynamic production/pricing policies in a closed-loop system

Hybrid manufacturing/remanufacturing systems play a key role in implementing closed-loop production systems which have been considered due to increasingly environmental concerns and latent profit of used products. Manufacturing and remanufacturing rates, selling price of new products, and acquisition price of used products are the most critical variables to optimize in such hybrid systems. In this paper, we develop a dynamic production/pricing problem, in which decisions should be made in each period confronting with uncertain demand and return. The manufacturer is able to control the demand and return by adjusting selling price and acquisition price respectively, also she can stock inventories of used and new products to deal with uncertainties. Modeling a nominal profit maximization problem, we go through robust optimization approach to reformulate it for the uncertain case. Final robust optimization model is obtained as a quadratic programming model over discrete periods which can be solved by optimization packages of QP. A numerical example is defined and sensitivity analysis is performed on both basic parameters and parameters associated with uncertainty to create managerial views.     

Acute lung injury induced by Staphylococcal enterotoxin B: disruption of terminal vessels as a mechanism of induction of vascular leak

The current hypothesis of alveolar capillary membrane dysfunction fails to completely explain the severe and persistent leak of protein-rich fluid into the pulmonary interstitium, seen in the exudative phase of acute lung injury (ALI). The presence of intact red blood cells in the pulmonary interstitium may suggest mechanical failure of pulmonary arterioles and venules. These studies involved the pathological and ultrastructural evaluation of the pulmonary vasculature in Staphylococcal enterotoxin B (SEB)-induced ALI. Administration of SEB resulted in a significant increase in the protein concentration of bronchoalveolar lavage fluid and vascular leak in SEB-exposed mice compared to vehicle-treated mice. In vivo imaging of mice demonstrated the pulmonary edema and leakage in the lungs of SEB-administered mice. The histopathological studies showed intense clustering of inflammatory cells around the alveolar capillaries with subtle changes in architecture. Electron microscopy studies further confirmed the diffuse damage and disruption in the muscularis layer of the terminal vessels. Cell death in the endothelial cells of the terminal vessels was confirmed with TUNEL staining. In this study, we demonstrated that in addition to failure of the alveolar capillary membrane, disruption of the pulmonary arterioles and venules may explain the persistent and severe interstitial and alveolar edema.