FT-IR, FT-Raman spectra and quantum chemical calculations of 3,4-dimethoxyaniline

In this work, we will report a combined experimental and theoretical study on molecular and vibrational structure of 3,4-dimethoxyaniline (3,4-DMA). The Fourier transform infrared and Fourier transform Raman spectra of 3,4-DMA was recorded in the solid phase. The optimized geometry was calculated by HF and B3LYP methods using 6-31G(d,p) and 6-311++G(d,p) basis sets. The harmonic vibrational frequencies, infrared intensities, Raman scattering activities and the thermodynamic functions of the title compound were performed at and HF/B3LYP/6-311++G(d,p) level of theories. The scaled theoretical wavenumber showed very good agreement with the experimental values. A detailed interpretation of the infrared and Raman spectra of 3,4-DMA was reported. The theoretical spectrograms for IR and Raman spectra of the title molecule have been constructed.     

Effect of nanoscale CeO<Subscript>2</Subscript> on PVDF-HFP-based nanocomposite porous polymer electrolytes for Li-ion batteries

New poly (vinylidenefluoride-co-hexafluoro propylene) (PVDF-HFP)/CeO₂-based microcomposite porous polymer membranes (MCPPM) and nanocomposite porous polymer membranes (NCPPM) were prepared by phase inversion technique using N-methyl 2-pyrrolidone (NMP) as a solvent and deionized water as a nonsolvent. Phase inversion occurred on the MCPPM/NCPPM when it is treated by deionized water (nonsolvent). Microcomposite porous polymer electrolytes (MCPPE) and nanocomposite porous polymer electrolytes (NCPPE) were obtained from their composite porous polymer membranes when immersed in 1.0 M LiClO₄ in a mixture of ethylene carbonate/dimethyl carbonate (EC/DMC) (v/v = 1:1) electrolyte solution. The structure and porous morphology of both composite porous polymer membranes was examined by scanning electron microscope (SEM) analysis. Thermal behavior of both MCPPM/NCPPM was investigated from DSC analysis. Optimized filler (8 wt% CeO₂) added to the NCPPM increases the porosity (72%) than MCPPM (59%). The results showed that the NCPPE has high electrolyte solution uptake (150%) and maximum ionic conductivity value of 2.47 × 10⁻³ S cm⁻¹ at room temperature. The NCPPE (8 wt% CeO₂) between the lithium metal electrodes were found to have low interfacial resistance (760 Ω cm²) and wide electrochemical stability up to 4.7 V (vs Li/Li⁺) investigated by impedance spectra and linear sweep voltammetry (LSV), respectively. A prototype battery, which consists of NCPPE between the graphite anode and LiCoO₂ cathode, proves good cycling performance at a discharge rate of C/2 for Li-ion polymer batteries.     

Crystal-to-crystal transformations in heterometallic yttrium(III)-copper(I) iodide derivatives in a confined solvent-free environment: influence of solvated yttrium cations on the nuclearity and dimensionality of iodocuprate clusters

The solvated yttrium iodide precursors [Y(L)(8)]I(3) (L = DMSO or DMF), prepared in situ by stirring YI(3)(Pr(i)OH)(4) in DMSO or DMF, react with CuI in the presence of NH(4)I to give ionic hetero-metallic species [Y(DMSO)(8)][Cu(2)(mu-I)I(4)] (1) and [Y(DMF)(8)][Cu(4)(mu(3)-I)(2)(mu-I)(3)I(2)] (2) in excellent yields. Re-crystallization of 1 from DMF afforded the mixed-solvate complex [Y(DMSO)(6)(DMF)(2)][CuI(3)][I] (3). Compounds 2 and 3 undergo unique crystal-to-crystal transformation via progressive substitution of DMF by water molecules in a confined, solvent-free environment. Thus, crystals of 3 transform into [Y(DMSO)(6)(H(2)O)(2)][CuI(3)][I] (4), whereas a discrete ion-pair assembly of 2 is first converted into a 1-D zig-zag structure [Y(DMF)(6)(H(2)O)(2)](3+)[Cu(7)(mu(4)-I)(3)(mu(3)-I)(2)(mu-I)(4)(I)](1infinity)(3-) (5) and finally into a 2-D sheet containing mixed-valent copper atoms, [Y(DMF)(6)(H(2)O)(3)](3+)[Cu(I)(7)Cu(II)(2)(mu(3)-I)(8)(mu-I)(6)](2infinity)(3-) (6). The bi- and tetrafurcate H-bonding between water ligands on yttrium and iodides of the Cu-I cluster plays a pivotal role in the evolution of structures 4-6. Formation of a wide range of iodocuprate structures in 1-6, from discrete mono-, di- or tetranuclear units to one- and two-dimensional extended arrays, reflects the influence of solvated yttrium cations on the nuclearity and dimensionality of Cu-I clusters. TG-DTA-MS studies and DFT calculations for these complexes have also been carried out in order to determine their thermal stability and have insight about aforesaid transformations.     

Rapid and simple liquid chromatography tandem mass spectrometry method for the quantification of zidovudine in rat plasma

A high-performance liquid chromatography/electrospray ionization tandem mass spectrometry method was developed and validated for the quantification of zidovudine in rat plasma. Following solid-phase extraction, the analytes were separated using an isocratic mobile phase on a reverse phase column and analyzed by MS/MS in the multiple reaction monitoring mode using the respective [M+H]+ ions, m/z 268/127 for zidovudine and m/z 230/112 for the internal standard. The method exhibited a linear dynamic range of 5-500 ng/mL for zidovudine in rat plasma. The lower limit of quantification was 5 ng/mL with a relative standard deviation of less than 8%. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. A run time of 1.5 min for each sample made it possible to analyze more than 400 plasma samples per day. The validated method was applied for pharmacokinetic studies of the novel drug delivery systems of zidovudine in rats.     

Infrared matrix isolation study of the thermal and photochemical reactions of ozone with dimethylzinc

The matrix isolation technique has been combined with infrared spectroscopy and theoretical calculations to explore the reaction of (CH3)2Zn with O3 over a range of time scales. Upon twin jet deposition, an initial cage pair complex was observed, along with formation of the novel H3COZnCH3 species. Subsequent UV irradiation destroyed the complex and greatly increased the yield of H3COZnCH3. An extensive set of bands were seen for this molecule, and (18)O spectroscopic data were obtained as well. The identification of this species was supported by theoretical calculations at the B3LYP/6-311++g(d,2p) level. Merged jet deposition led to a very different set of products, including H2CO, CH3OH and C2H6, identifications that were confirmed by (18)O substitution. In addition, a new variable length concentric deposition technique was developed to permit study of the time scales between twin (relatively short) and merged (relatively longer) reaction times. Mechanistic inferences for this reaction are discussed.     

Solid- and solution phase transformations in novel hybrid iodoplumbate derivatives templated by solvated yttrium complexes

Solvated yttrium iodide precursors [Y(L)8]I3 [L = dimethylformamide (DMF) or dimethylsulfoxide (DMSO)], prepared in situ by stirring YI3(Pr(i)OH)4 in DMF/DMSO, react with 3 equiv of PbI2 in the presence of NH4I to give novel hybrid derivatives based on either a one-dimensional (1D) straight chain, [Y(DMF)8][Pb3(mu-I)9](1infinity) x DMF (1), or discrete pentanuclear iodoplumbates, [Y(DMSO)8]2[(DMSO)2Pb5(mu3-I)2(mu-I)8I6] (2a). The complex 2a and a closely related [Y(DMSO)8][Y(DMSO)7(DMF)][(DMSO)2Pb5(mu3-I)2(mu-I)8I6] (2b) were obtained in good yield by solution phase transformation of 1 in DMSO under slight different conditions. Derivatives 1 and 2 also undergo unique solid-state transformation in a confined environment of paratone to give 1D polymers based on zigzag iodoplumbate chains; crystals of 1 transform into [Y(DMF)6(H2O)2][Pb3(mu3-I)(mu-I)7I](1infinity) (3) via an exchange reaction, whereas those of 2a and 2b are converted into [Y(DMSO)7][Pb3(mu3-I)(mu-I)7I](1infinity) (4) via a decomposition pathway. The trifurcate H-bonding between water ligands on yttrium cation and iodide of the iodoplumbate anion plays a pivotal role in transforming the straight 1D polymeric Pb-I chain of 1 into a zigzag chain in 3. The thermogravimetry-differential thermal analysis studies indicate that complexes with DMF ligands are thermally more stable than those with DMSO ones, the mixed DMF-H2O ligand complex 3 being the most stable one because of the presence of strong H-bonding. Diffuse-reflectance UV-visible spectral analyses of 1-4 show an optical band gap in the 1.86-2.54 eV range, indicating these derivatives as potential semiconductors. In contrast to non-emissive 3 and 4, derivatives 1, 2a, and 2b show remarkable luminescent emission with peak maxima at 703 nm, assigned as an iodine 5p-lead 6s to lead 6p charge transfer (XM-M-CT).     

Study of mesomorphism and laterally substituted nitro group

A novel thermotropically mesomorphic, meta-substituted nitro group of chalconyl ester series, RO-C₆H₄-COO-C₆H₃-(NO₂)-CO-CH=CH-C₆H₄OC₁₂H₂₅(n) (para) is synthesized and studied with an aim to establish the relation between molecular structure and the mesomorphism with reference to changing molecular flexibility in presence of nitro lateral group. Novel homologous series consist of thirteen homologs (C₁–C₁₈) whose mesomorphism commences from C₅ homolog as enantiotropic nematogenic with absence of smectic property, even in the monotropic condition. Transition temperatures of novel substances were determined by an optical polarizing microscope, equipped with a heating stage (POM). Textures of a nematic phase are threaded or Schlieren. N-I transition curve exhibited narrow, sharp and short odd-even effect; with deviating trend in a phase diagram. Analytical, spectral and thermal data confirmed the molecular structures of homologs. Thermal stability for nematic is 182.89°C, whose mesophase lengths minimum to maximum ranges from 17°C to 45°C and it is an upper middle ordered melting type series. Group efficiency order for nematic is series 1 > series Y > series X, as derived from comparative study of structurally similar analogous series.     

1,3,5-trinitro-1,3,5-triazine decomposition and chemisorption on Al(111) surface: first-principles molecular dynamics study

We have investigated the decomposition and chemisorption of a 1,3,5-trinitro-1,3,5-triazine (RDX) molecule on Al(111) surface using molecular dynamics simulations, in which interatomic forces are computed quantum mechanically in the framework of the density functional theory (DFT). The real-space DFT calculations are based on higher-order finite difference and norm-conserving pseudopotential methods. Strong attractive forces between oxygen and aluminum atoms break N-O and N-N bonds in the RDX and, subsequently, the dissociated oxygen atoms and NO molecules oxidize the Al surface. In addition to these Al surface-assisted decompositions, ring cleavage of the RDX molecule is also observed. These reactions occur spontaneously without potential barriers and result in the attachment of the rest of the RDX molecule to the surface. This opens up the possibility of coating Al nanoparticles with RDX molecules to avoid the detrimental effect of oxidation in high energy density material applications.     

The interference wave and the bright and dark soliton for two integro-differential equation by using BNNM

Interference wave is an important research target in the field of navigation, electromagnetic and earth science. In this work, the nonlinear property of neural network is used to study the interference wave and the bright and dark soliton solutions. The generalized broken soliton-like equation is derived through the generalized bilinear method. Three neural network models are presented to fit explicit solutions of generalized broken soliton-like equations and Boiti–Leon–Manna–Pempinelli-like equation with 100% accuracy. Interference wave solutions of the generalized broken soliton-like equation and the bright and dark soliton solutions of the Boiti–Leon–Manna–Pempinelli-like equation are obtained with the help of the bilinear neural network method. Interference waves and the bright and dark soliton solutions are shown via three-dimensional plots and density plots.

     

Quantum Phase Properties of Photon Added and Subtracted Displaced Fock States

Quantum phase properties of photon added and subtracted displaced Fock states (and their limiting cases) are investigated from a number of perspectives, and it is shown that the quantum phase properties are dependent on the quantum state engineering operations performed. Specifically, the analytic expressions for quantum phase distributions and angular Q distribution as well as measures of quantum phase fluctuation and phase dispersion are obtained. The uniform phase distribution of the initial Fock states is observed to be transformed by the unitary operation (i.e., displacement operator) into non‐Gaussian shape, except for the initial vacuum state. It is observed that the phase distribution is symmetric with respect to the phase of the displacement parameter and becomes progressively narrower as its amplitude increases. The non‐unitary (photon addition/subtraction) operations make it even narrower in contrast to the Fock parameter, which leads to broadness. The photon subtraction is observed to be a more powerful quantum state engineering tool in comparison to the photon addition. Further, one of the quantum phase fluctuation parameters is found to reveal the existence of antibunching in both the engineered quantum states under consideration. Finally, the relevance of the engineered quantum states in the quantum phase estimation is also discussed.