LiClO4-Accelerated Three-Component Mannich-Type Reaction of Diethyl Malonate with Imines: An Efficient Synthesis of β-Amino Esters Under Solvent-Free Conditions

LiClO₄ is used as catalyst for direct Mannich-type reaction of aryl aldehydes, aryl amines, and diethyl malonic ester under solvent-free conditions. This three-component reaction afforded the corresponding β-amino esters in good yields with simple and environmentally benign procedure.     

Bismuth(III) Chloride–Catalyzed Three‐Component Coupling: Synthesis of α‐Amino Phosphonates

A simple and efficient method has been developed for the one‐pot synthesis of α‐amino phosphonates from the reaction of a carbonyl compound, amine, and dialkyl phosphite. The highly catalytic nature of bismuth(III) chloride and the fact that it is relatively nontoxic, low cost, easy to handle, and insensitive to small amounts of air and moisture make this method especially attractive for large‐scale synthesis.     

螺芴对含三齿磷配体的铱配合物光电性能的影响

合成了一种含4,5-二氮-9,9-螺二芴(sb)配体的三齿磷铱配合物Ir(tpit)(sb)Cl(tpitH2=亚磷酸三苯基酯),通过核磁共振氢谱和磷谱及高分辨质谱对其结构进行了确定。X射线单晶衍射分析表明,sb配体的存在扭曲了分子结构,有助于降低分子聚集及发光淬灭。与存在分子内π-π堆积的模型配合物Ir(tpit)(bpy)Cl(bpy=2,2′-联吡啶)对比进行了光电性能的研究。结果表明在聚甲基丙烯酸甲酯(质量分数1%)中配合物Ir(tpit)(sb)Cl的发光波长为512 nm,相对配合物Ir(tpit)(bpy)Cl的波长(520 nm)有了8 nm蓝移。配合物Ir(tpit)(sb)Cl的发光量子效率为30%,与配合物Ir(tpit)(bpy)Cl的94%相比有明显降低,说明了分子内π-π堆积作用在降低柔性基团非辐射跃迁率方面的重要作用。基于配合物Ir(tpit)(sb)Cl的有机电致发光器件,最大电流效率和外量子效率分别为14 cd·A-1和4.5%。而由于分子内π-π堆积作用,基于配合物Ir(tpit)(bpy)Cl器件的最大电流效率和外量子效率分别高达60 cd·A-1和18.2%。     

Hydrogen bonding in thiourea: diethyl oxalate complex in 2:1 ratio

The crystal structure of thiourea:diethyl oxalate in 2:1 ratio is the first of its kind where the diethyl oxalate exists as a solid which otherwise is a liquid at room temperature. It crystallizes in triclinic centrosymmetric space group P-1 with the following unit cell dimensions a = 7.1870(7) Å, b = 7.4890(8) Å, c = 8.3637(7) Å, α = 63.783(7)^∘, β = 67.41(1)^∘, γ = 64.933(7)^∘. The R-factor = 0.0386 for 1850 F_o > 4σ (F_o) and 0.0417 for all 2020 data. There is a center of inversion at the center of the C–C bond of diethyl oxalate. This system is stabilized by N–H ⋅s S and N–H ⋅s O hydrogen bonds.     

The Morphology Evolution of Nickel Phosphite Hexagonal Polyhedrons and Their Primary Electrochemical Capacitor Applications

Nickel posphite (Ni₁₁(HPO₃)₈(OH)₆) hexagonal polyhedrons are successfully synthesized under hydrothermal conditions. The effect of surfactants on the growth mechanism of Ni₁₁(HPO₃)₈(OH)₆ are also explored. More importantly, Ni₁₁(HPO₃)₈(OH)₆ hexagonal polyhedrons are successfully applied as electrochemical supercapacitor electrode materials, which have a good specific capacitance (295 F g^?1 at 0.625 A g^?1), good rate capability, and cycling properties (maintained about 99.3% at 0.625 A g^?1 after 1000 cycles).     

Electrosyntheses of high‐quality freestanding poly(fluorene‐co‐3‐methylthiophene) films with tunable fluorescence properties

The copolymerization of 3‐methylthiophene (MeT) and fluorene (FE) was successfully achieved in boron trifluoride diethyl etherate by the direct anodic oxidation of the monomer mixtures on a platinum electrode. The optimal feed ratio together with the best suitable potential for their copolymerization was determined. The as‐formed copolymer films, which were copolymerized with a feed ratio of FE/MeT = 2:1 at a constant potential of 1.3 V (vs a saturated calomel electrode), had the advantages of both poly(3‐methylthiophene) and polyfluorene, such as good electrochemical behavior, high conductivity, excellent thermal stability, and high film quality. The structure of the copolymer was investigated with ultraviolet–visible, infrared spectroscopy, and thermal analysis. Fluorescence spectroscopy studies revealed that the dedoped copolymer film in the solid state was a good blue‐light emitter with a strong emission at 435 nm and a shoulder at 459 nm. The emitting properties of the copolymer could be tuned by parameters during the electrochemical polymerization, such as the applied potential and monomer feed ratio. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4904–4915, 2006     

Review on gel polymer electrolytes for lithium batteries

This paper reviews the state-of-art of polymer electrolytes in view of their electrochemical and physical properties for the applications in lithium batteries. This review mainly encompasses on five polymer hosts namely poly(ethylene oxide) (PEO), poly(acrylonitrile) (PAN), poly(methyl methacrylate) (PMMA), poly(vinylidene fluoride) (PVdF) and poly(vinylidene fluoride-hexafluoro propylene) (PVdF-HFP) as electrolytes. Also the ionic conductivity, morphology, porosity and cycling behavior of PVdF-HFP membranes prepared by phase inversion technique with different non-solvents have been presented. The cycling behavior of LiMn₂O₄/polymer electrolyte (PE)/Li cells is also described.     

Deactivation kinetics of a COcoupling reaction after addition of H2 to the system

The influence of hydrogen on the catalytic coupling reaction of CO was tested ar reaction temperatures of 105 120^oC and a residence time of 1.8 s. The formation rate of diethyl oxalate (DEO) decreases with the addition of hydrogen to the system. Increasing hydrogen concentration and reaction temperature, the apparent rate of main reaction or the yield of DEO decreases more quickly. But the deactivation rate does not change with the relative activity. By correlating the experimental data, the deactivation kinetics was obtained. This revised version was published online in June 2006 with corrections to the Cover Date.     

The millimeter- and submillimeter-wave spectrum of the trans-gauche conformer of diethyl ether

The results of a first investigation of the rotational spectrum of the trans-gauche conformer of diethyl ether are reported. Two spectrometers have been used to measure the spectrum in the millimeter-wave and submillimeter-wave regions and a total of 1090 absorption line frequencies in the range 108-366 GHz were obtained and analyzed. Of these lines, 902 were measured with a spectrometer employing the fast scan submillimeter spectroscopic technique (FASSST) at Ohio State and the remaining 188 were measured with the phase-lock two-loop system (PLL) in Warsaw. The spectrum was fit to within experimental accuracy with the use of the A-reduced Watson Hamiltonian. Based on relative intensity measurements, the percentage of diethyl ether at room temperature in the trans-gauche conformer was found to be 30.5(13)%, in good agreement with prior spectroscopic values and an ab initio determination based on an energy difference of 5.40 kJ mol⁻¹ (452 cm⁻¹) between the excited trans-gauche and ground trans-trans conformers. This work also stimulated a critical evaluation of the data acquisition and calibration procedure of the FAAAST spectrometer, the results of which will be discussed.     

Organometallic chemistry in the melt phase

In this review organometallic chemistry reactions in the melt phase are described. As will be indicated this is a viable approach to make new and known complexes. Examples from the literature highlighting procedures used to generate melts and results that have been obtained in this area of synthesis are described. Clearly there will be limitations to the use of the melt phase, and these limitations are also discussed.