Crystallographic and Conformational Analysis of [(Z)-2-ethoxy-6-[(2-hydroxyphenylamino)methylene]cyclohexa-2,4-dienone]

Abstract  The single crystal X-ray diffraction analysis of the title compound, C₁₅H₁₅NO₃, shows that the structure is adopted to its NH tautomeric form and crystallizes in the orthorhombic space group P bcn with a = 21.2424(15) ?, b = 12.7696(9) ?, c = 9.3605(10) ?, Z = 8, V = 2539.1(4) ?³, D _c  = 1.346 g/cm³. The molecular conformation in the crystal is stabilized by an intramolecular H-bond and the crystal structure is stabilized by the bifurcated O–H···O type intermolecular H-bonds. In order to understand the effects on conformational flexibility of the title molecule, molecular energy profile was calculated as a function of the selected torsion angle by means of AM1 semi-empirical method. Index Abstract  Molecular and crystal structure of [(Z)-2-ethoxy-6-[(2-hydroxyphenylamino)methylene]cyclohexa-2,4-dienone], C₁₅H₁₅NO₃, have been determined by single crystal X-ray diffraction study, and conformational analysis of the title molecule with respect to the selected torsion angle has been achieved by AM1 semi-empirical calculations.      

Dendrimer Disassembly in the Gas Phase: A Cascade Fragmentation Reaction of Fréchet Dendrons

The mass spectrometric characterization of Fréchet‐type dendrons is reported. In order to provide the charges necessary for electrospray ionization, dendrons bearing an OH group at the focal point can be deprotonated and observed in the negative ion mode. Alternatively, the corresponding bromides can be converted to quaternary ammonium ions that can easily be detected in the positive mode. If the latter ions are subjected to collision‐induced dissociation experiments, a fragmentation cascade begins with the dissociation of the focal amine. The focal benzyl cation quickly decomposes in a fragmentation cascade from the focal point to the periphery until the peripheral benzyl (or naphthylmethyl) cations are formed. Five different mechanisms are discussed in detail, three of which can be excluded based on experimental evidence. The cascade fragmentation is reminiscent of self‐immolative dendrimers.     

X-ray structural,spectroscopic and computational approach (NBO,MEP, NLO,NPA, fukui function analyses) of (E)-2-((4-bromophenylimino)methyl)-3-methoxyphenol

The title compound was isolated and investigated by experimental X-ray diffraction method and density functional theory (DFT) calculational properties and spectroscopic methodologies. The experimental investigations of the compound indicated the molecule seems to be in enol form. DFT calculations are performed both for enol and keto tautomers of the title compound. Additionally chemical activity, electronic transmission and property effect on different solvents, molecular electrostatic potential (MEP), non-linear optical properties (NLO), Mulliken population method, natural population analysis (NPA), natural bond orbital (NBO) and Fukui function analyses have been studied.     

Analytical and numerical solutions of mathematical biology models: The Newell-Whitehead-Segel and Allen-Cahn equations

In this paper, we combine the unified and the explicit exponential finite difference methods to obtain both analytical and numerical solutions for the Newell-Whitehead-Segel–type equations which are very important in mathematical biology. The unified method is utilized to obtain various solitary wave solutions for these equations. Numerical solutions of the specific case studies are investigated by using the explicit exponential finite difference method ensures the accuracy and reliability of the proposed scheme. After obtaining the approximate solutions, convergence analysis and error estimation (the error norms and absolute errors) are presented by comparing these results with the analytical obtained solutions and other methods in the literature through tables and graphs. The obtained analytical and numerical results are in good agreement.     

The spin-1 Blume–Capel model on the Bethe lattice in ± J distribution with an adjustable parameter between FM and AFM phases

The spin-1 Blume–Capel (BC) model is studied on the Bethe lattice (BL) for the ?±? J distribution with a competing adjustable parameter α which alters the strength of bilinear exchange interaction parameter for the ferromagnetic phase (J?>?0) with respect to antiferromagnetic phase (J?<?0). The J?>?0 and αJ?<?0 values are also distributed throughout the BL with probabilities p and $1?p,$ respectively. The order-parameters are obtained on the BL in terms of exact recursion relations (ERR’s) and their temperature (T) variations are studied to calculate the phase diagrams on the (α, T) planes for given values of p, crystal field (D) and coordination number $q=3$ corresponding to honeycomb lattice. It is found that the model gives both first- and second-order phase transitions and also tricritical points. In addition to the well known ordinary phases and TCP’s, the spin glass phase and two more special points are also observed.     

A Theoretical Study on <Emphasis Type="Italic">N</Emphasis>′-[(<Emphasis Type="Italic">Z</Emphasis>)-(4-Methylphenyl)Methylidene]-4-Nitrobenzohydrazide (NMPMN)

Quantum mechanical calculations of ground state energy, vibration wavenumbers, and electronic absorption wavelengths of N′-[(Z)-(4-methylphenyl)methylidene]-4-nitrobenzohydrazide with C15H13N3O3 empirical formula was performed by using Gaussian 09 program. Becke’s three-parameter exchange functional in conjunction with the Lee-Yang-Parr correlation functional and Heyd-Scuseria-Ernzerhof functional levels of density functional theory (DFT) with the 6-311++G(d,p) basis set were used in the performing of above mentioned calculations. The highest occupied and lowest unoccupied molecular orbital (HOMO and LUMO) energies have been also calculated at the same levels. Stability of the molecule arising from hyperconjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. Nonlinear optical (NLO) behavior of the title molecule has been examined by the determining of electric dipole moment (μ), polarizability (α), and static first-order hyperpolarizability (β). Finally, molecular electrostatic potential (MEP) surface as well as Mulliken and NBO atomic charges were calculated by using Gaussian 09 program.     

The Third Generation (e,e′K~+) A Hypernuclear Spectroscopy at Jlab

We are now preparing for the third generation (e,e′K~+) A hypernuclear spectroscopic experiment at Hall C,Jefferson Lab (USA).The goal of the experiment is the precise spectroscopy of hypernuclei in wide mass region.We have constructed a new high resolution electron spectrometer "HES" dedicated to (e,e′K~+) hypernuclear study in Japan and it was shipped to JLab in February,2008.We will discuss about the physics of the (e,e′K~+) hypernuclear study at JLab and report the current preparation status of the third generatrion experiment.     

The antiferromagnetic Ising model for a bilayer Bethe lattice

The totally antiferromagnetic Ising model is analyzed on a bilayer Bethe lattice in detail by studying the order-parameters, response functions, i.e. susceptibility and specific heat, and free energy by using the recursion relations in a pairwise approach. The ground state phase diagrams of the model are also obtained on the (_J2/|_J1|,_J3/q|_J1|)$(J_2/|J_1|,J_3/q|J_1|)$ plane for given values of H/q|_J1|$H/q\left|J_1\right|$ and on the (H/q|_J1|,_J3/q|_J1|)$(H/q|J_1|,J_3/q|J_1|)$ plane for given _J2/|_J1|$J_2/\left|J_1\right|$. As a result, we have obtained the temperature-dependent phase diagrams for various values of the coordination number q   on the (_J3/|_J1|,kT/|_J1|)$(J_3/|J_1|,\mathit{kT}/|J_1|)$ and (H/|_J1|,kT/|_J1|)$(H/|J_1|,\mathit{kT}/|J_1|)$ planes for given values of the rest of the system parameters.     

Effect of oxide thickness on the capacitance and conductance characteristics of MOS structures

In this work, the investigation of the interface states density and series resistance from capacitance–voltage (C–V) and conductance–voltage (G–V) characteristics in Au/SnO₂/n-Si (MOS) structures prepared at various SnO₂ layer thicknesses by spray deposition technique have been reported. It is fabricated five samples depending on deposition time. The thicknesses of SnO₂ films obtained from the measurement of the oxide capacitance in the strong accumulation region for MOS Schottky diodes are 37, 79, 274, 401, and 446 Å, for D1, D2, D3, D4, and D5 samples, respectively. The C–V and G–V measurements of Au/SnO₂/n-Si MOS structures are performed in the voltage range from −6 to +10 V and the frequency range from 500 Hz to 10 MHz at room temperature. It is observed that peaks in the forward C–V characteristics appeared because of the series resistance. It has been seen that the value of the series resistance R_s of samples D1 (47 Ω), D2 (64 Ω), D3 (98 Ω), D4 (151 Ω), and D5 (163 Ω) increases with increasing the oxide layer thickness. The interface state density D_it ranges from 2.40×10¹³ cm⁻² eV⁻¹ for D1 sample to 2.73×10¹² cm⁻² eV⁻¹ for D5 sample and increases with increasing the oxide layer thickness.     

Electrochemical Investigation of Ruxolitinib: Sensitive Voltammetric Assay in Drug Product and Human Serum by Using Different Solid Electrodes

Ruxolitinib (RUX), a compound of the pyrrolopyrimidines class with activity as a tyrosine kinase inhibitory drug, is used to treat myelofibrosis. This study is reported for the detailed electrochemical behavior of RUX. The effects of supporting electrolyte, pH, and scanning rate on the peak potentials and currents of RUX were investigated by BDDE and GCE using different voltammetric techniques. Under optimum experimental conditions, calibration curves for RUX were obtained as 4 μM–80 μM and 1 μM–80 μM with a limit of detection (LOD) of 0.517 μM and 0.192 μM by the GCE and BDDE, respectively using DPV.