1‐Butyl‐3‐methylimidazolium Hydrogen Sulfate [Bmim]HSO4: An Efficient Reusable Acidic Ionic Liquid for the Synthesis of 1,8‐Dioxo‐Octahydroxanthenes

1‐Butyl‐3‐methylimidazolium hydrogen sulfate [bmim]HSO₄ as an acidic ionic liquid was prepared and used as a catalyst for the synthesis of 1,8‐dioxo‐octahydroxanthenes in excellent yields and short reaction times at 80 °C. The ionic liquid was easily separated from the reaction mixture by water extraction and was recycled four times without any loss in activity.     

Synthesis of functionalized 5-imino-2,5-dihydro-furans through the reaction of isocyanides with activated acetylenes in the presence of ethyl bromopyruvate

Summary The reaction between alkyl(aryl) isocyanides and dibenzoylacetylene in the presence of ethyl bromopyruvate leads to ethyl 3,4-dibenzoyl-2-bromomethyl-5-alkyl(aryl)imino-2,5-dihydro-furan-2-carboxylates in high yields. Dialkyl acetylenedicarboxylates react with tert-butyl isocyanide and ethyl bromopyruvate to produce 3,4-dialkyl 2-ethyl 2-bromomethyl-5-tert-butylimino-2,5-dihydro-furan-2,3,4-tricarboxylates.     

A one-pot synthesis of functionalized thiazoles from acid chlorides, secondary amines, ethyl bromopyruvate, and ammonium thiocyanate

An efficient one-pot synthesis of ethyl 2-(4-aryl-2-dialkylamino-1,3-thiazole-5-yl)-2-oxoacetates using acid chlorides, secondary amines, ethyl bromopyruvate, and ammonium thiocyanate is described.     

Exact Solution of Klein-Gordon Equation for Charged Particle in Magnetic Field with Shape Invariant Method

Based on the shape invariance property we obtain exact solutions of the three-dimensional relativistic Klein Gordon equation for a charged particle moving in the presence of a certain varying magnetic field, and we also show its non-relativistic limit.     

Nonadiabatic coupling and diabatic electronic population dynamics on 11A2 and 11B1 states of ozone molecule

In this work, we examine nonadiabatic population dynamics for 1¹B₁ and 1¹A₂ states of ozone molecule (O₃). In O₃, two lowest singlet excited states, ¹A₂ and ¹B₁, can be coupled. Thus, population transfer between them occurs through the seam involving these two states. At any point of the seam (conical intersection), the Born-Oppenheimer approximation breaks down, and it is necessary to investigate nonadiabatic dynamics. We consider a linear vibronic coupling Hamiltonian model and evaluate vibronic coupling constant, diabatic frequencies for three modes of O₃, bilinear and quadratic coupling constants for diabatic potentials, displacements, and Huang-Rhys coupling constants using ab initio calculations. The electronic structure calculations have been performed at the multireference configuration interaction and complete active space with second-order perturbation theory with a full-valence complete active space self-consistent field methods and augmented Dunning's standard correlation-consistent-polarized quadruple zeta basis set to determine ab initio potential energy surfaces for the ground state and first two excited states of O₃, respectively. We have chosen active space comprising 18 electrons distributed over 12 active orbitals. Our calculations predict the linear vibronic coupling constant 0.123 eV. We have obtained the population on the 1¹B₁ and 1¹A₂ excited electronic states for the first 500 fs after photoexcitation.     

Anharmonic 1D actuator model including electrostatic and Casimir forces with fractional damping perturbed by an external force

We modeled a one-dimensional actuator including the Casimir and electrostatic forces perturbed by an external force with fractional damping. The movable electrode was assumed to oscillate by an anharmonic elastic force originated from Murrell–Mottram or Lippincott potential. The nonlinear equations have been solved via the Adomian decomposition method. The behavior of the displacement of the electrode from equilibrium position, its velocity and acceleration were described versus time. Also, the changes of the displacement have been investigated according to the frequency of the external force and the voltage of the electrostatic force. The convergence of the Adomian method and the effect of the orders of expansion on the displacement versus time, frequency, and voltage were discussed. The pull-in parameter was obtained and compared with the other models in the literature. This parameter was described versus the equilibrium position and anharmonicity constant.     

Nanoparticle using parallel split rings and implementation of chain for creating Fano resonance with polarization independence for energy harvesting in mid-infrared

In optical devices, the polarization of the incident wave affects the Nano particle characteristics. Therefore, designing a polarization-independent device is significant in the process of designing optical structures. On the other hand, the concept of Fano resonance and dark mode has been utilized for achieving more energy enhancement. In this paper, we have developed a symmetrical Nano antenna by employing Fano resonance, which is independent of the incident wave polarization. The proposed Nano antenna is modified in mid infrared regime for biosensing and energy harvesting applications. The designed metamaterial antenna is made by Nano split ring resonators with etched capacitive gaps, which are utilized for concentrating energy. The introduced Nano antenna has a bright and dark mode with a weak enhancement of electric field. The effect of the incident wave polarization is investigated at wave incident angles between 0° and 45° to illustrate the independency of the polarization due to the symmetrical shape of the Nano antenna. In order to trigger the dark mode and enhance the electric field, a Nano chain is incorporated in the final structure. This arrangement has led to increasing of electric field drastically. Furthermore, the figure of merit has been calculated as an advantageous factor in sensing the surrounding materials with various refractive indices. Our findings illustrated that the chain arrangement has caused a peak in the linear form of the extinction cross section of the Nano antenna. This in turn has resulted in the appearance of Fano resonance with no impact on the resonance frequency that has been originally adjusted by capacitive gaps and inductive strips.     

The effect of relative phase on the stability of temporal dark soliton in $${{\mathcal {}}}$$-symmetric nonlinear directional fiber coupler

In this paper, we numerically investigate the effect of relative phase on the stability of dark solitons in \({\mathcal {PT}}\)-Symmetric nonlinear directional coupler (NLDC), by considering gain in the bar and loss in the cross in the range of \(\theta =0^\circ\) to \(180^\circ\). The \({\mathcal {PT}}\)-Symmetric perturbed eigenfunctions are used to study the soliton stability. The results of simulations are shown that in the first half region of the relative phase the soliton is unstable while in the second one, is stable. In the stable region gain and loss cancel each other and also the perturbed eigenfunctions have no effect on solitons while in the unstable region solitons are amplified in the bar and attenuated in the cross except for some small intervals which the roles are changed. The behavior of such perturbation can be interpreted as self all-optical phase soliton switching and optical logic gates.     

Invariant and stationary measures for the action on Moduli space

We prove some ergodic-theoretic rigidity properties of the action of Open image in new window on moduli space. In particular, we show that any ergodic measure invariant under the action of the upper triangular subgroup of Open image in new window is supported on an invariant affine submanifold.The main theorems are inspired by the results of several authors on unipotent flows on homogeneous spaces, and in particular by Ratner’s seminal work.     

Morphine Sensing by a Green Modified Molecularly Imprinted Poly L‐Lysine/Sodium Alginate‐activated Carbon/Glassy Carbon Electrode Based on Computational Design

A different molecularly imprinted composite film with the exploit of computational design is synthesized. The proposed composite is used for electrode modification to determine morphine. The ratio of monomer to template in optimum condition was obtained 4. The modification of the electrode was achieved by electropolymerizing L‐lysine in the presence of morphine on the surface of sodium alginate and activated carbon (SA‐AC) on glassy carbon electrode (GCE). The SA‐AC composite with special surface area suits for making sensitive sensors. Morphine showed an anodic peak in buffer solution of phosphate (pH=6.0) on MIP/SA‐AC/GCE. The optimization of the practical factors on the response and electrochemical behavior of template morphine on the modified electrode were precisely surveyed. The DPV outcomes exhibit high sensitivity for morphine detection within 0.1–1000.0 μM and limit of detection as 48 nM (S/N=3). The application of this disposable sensor in the case of urine samples was quite satisfactory.