Guest-induced asymmetry in a metal-organic porous solid with reversible single-crystal-to-single-crystal structural transformation

A metal-organic honeycomb-like 2D pillared-bilayer open framework has been constructed which shows dynamic sponge-like single-crystal-to-single-crystal transformation upon dehydration and rehydration. The dehydrated acentric nonporous phase transformed to the porous centric phase with the selective adsorbate concomitant with the structural transformation correlated with the single-crystal structure determination.     

Quantum dynamics of a system of coupled nonlinear oscillators: Spectral and information entropy‐based analysis

The quantum dynamics of the evolution of a system of a few coupled nonlinear oscillators is studied. The spectral entropy and the quantal information entropy, as well as their correlation functions, are computed and used to identify distinctive phases of the evolution. The two entropy functions lead to similar conclusions. It appears that adiabatic switching of the nonlinear interaction does not affect the nature of the short time dynamics but affects the dynamics over intermediate time scales. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005     

Studies on monobactams I. Synthesis and β-lactamase inhibitory activity of 4-substituted 3-[(N-methyl-1,2,3-triazol-4-yl)-methylene]-2-azetidinone-1-sulfonates

Two monobactam derivatives, potassium (3Z)-[(N-methyl-1,2,3-triazol-4-yl)methylene]-4-phenylthio-2-azetidinone-1-sulfonate and potassium (3E)-[(N-methyl-1,2,3-triazol-4-yl)methylene]-4-(1,2,3-triazol-1-yl)-2-azetidinone-1-sulfonate, were synthesized and tested for -lactamase inhibitory activity.SynPhar Laboratories Inc., #2, 4290-91A Street, Edmonton, Alberta, Canada T6E 5V2. Tokushima Research Institute, Taiho Pharmaceutical Co. Ltd., 224-2 Ebisuno Hiraishi, Kawauchi-cho, Japana 771-01. Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1536–1547, November, 1998.     

Direct incorporation of a ferric ion in the porphyrinogen core: tetrakis(cyclohexyl)iron porphyrinogen anion with different conformers and its reaction with iodine

Et(4)N[L' 'Fe(III)].3DCM (1) is directly synthesized by adding ferric chloride into a solution of a lithium salt of tetrakis(cyclohexyl)porphyrinogen (L' '). [L' '](4-) is a good chelating ligand for both Fe(III) and Fe(II) ions. It is an avid proton scavenger but not a reducing agent. 1 showed a magnetic moment (mu(eff)) of 4.3 micro(B) in the solid, which changed to 6.0 micro(B) in solution. This change in spin state is common for all iron porphrinogens. 1 showed polymorphism, and with pyridine in the lattice, it changed to Et(4)N[L' 'Fe(III)].DCM(0.5)Py(1.5) (2), possessing two different conformers. Calculation of these conformers at the density functional theory level showed the relative energies of all d orbital changes in three conformers, highlighting the influence of the disposition of a peripheral ligand. Iodine oxidation of 1 yielded [L' '(DeltaDelta)Fe(II)I][I(3).I(2)(+).I(3)(-)] (3) with the introduction of two C(alpha)-C(alpha) bonds with concomitant reduction of Fe(III) to Fe(II). Its mu(eff) (5.4 mu(B)) in the solid changed to 4.8 micro(B) in solution, suggesting a high spin state (S = 2) for Fe(II).     

Generalization of five q-series identities of Ramanujan and unexplored weighted partition identities

The Ramanujan Journal - Ramanujan recorded five interesting q-series identities in a section that is not as systematically arranged as the other chapters of his second notebook. These five...     

Ternary-material lithium-ion battery SOC estimation under various ambient temperature

Ambient temperature produces great effects on battery state-of-charge (SOC) estimation, due to the unstable estimation algorithm, the weakened traceability of battery model, and variable model parameters at various temperatures, especially lower temperatures. The widely used method based on the equivalent circuit model (ECM) offline in using different algorithm, like current integral, the extended Kalman filter (EKF), or the unscented Kalman filter (UKF), can obtain an accurate SOC estimation at room temperature, but it is difficult to guarantee the high precision at lower temperatures. To address this problem, the battery model is investigated at different temperature, and an offset item is proposed to develop the observer equation in the estimated model. Then, the square root of the Sigma points Kalman filter (SR-UKF) is applied, and on the basis of the individual model parameter-temperature table and the developed model, the high accuracy of SOC estimation is achieved. Additionally, considering the burden of original parameter modification (all model parameters modified) at various temperature which will increase the product cost and computational complexity of the battery management system (BMS), the relationship between individual model parameter and the error of SOC estimation is built, which is helpful for the simplification of parameter modification. The results indicate that the proposed method based on the developed estimated model and the simplified parameter modification can achieve an accurate, stable, and efficient SOC estimation.     

Palladium(II)‐Catalyzed meta‐C?H Olefination: Constructing Multisubstituted Arenes through Homo‐Diolefination and Sequential Hetero‐Diolefination

Divinylbenzene derivatives represent an important class of molecular building blocks in organic chemistry and materials science. Reported herein is the palladium‐catalyzed synthesis of divinylbenzenes by meta‐C H olefination of sulfone‐based arenes. Successful sequential olefinations in a position‐selective manner provided a novel route for the synthesis of hetero‐dialkenylated products, which are difficult to access using conventional methods. Additionally, 1,3,5‐trialkenylated compounds can be generated upon successful removal of the directing group.     

Supercontinuum generation in ultra-flat near zero dispersion PCF with selective liquid infiltration

We present a new design study of ultra-flat near zero dispersion PCF with selectively liquid infiltration with all uniform air-holes in the cladding. The dependence of the individual parameters upon dispersion has been presented in detail. The study establishes that varying Λ influences the total dispersion, whereas d has the desired effect of modifying the dispersion slope, and varying n_L modifies both. With the above study we could achieve near zero ultra-flat dispersion as small as 0 ± 0.41 ps/nm/km for broad wavelength range of 452 nm. The optimized near zero ultra-flat dispersion PCF has been targeted for smooth and flat broadband spectrum supercontinuum generation (SCG) for near Infrared (IR) applications. Broadband SC generations corresponding to three different designs of ultra-flat dispersion fiber have been carried out by using picoseconds pulse laser around the first zero dispersion wavelengths (ZDW). The numerical results show that FWHM of around 400 nm with less than a meter long fiber can be achieved with these fibers that cover most of the communication wavelength bands. The proposed design study will be applicable for applications in the field of tomography, Dense Wavelength Division Multiplexing (DWDM) system, spectroscopy, etc.