Characterization on Lead-Free Hybrid Perovskite [NH3(CH2)5NH3]CuCl4: Thermodynamic Properties and Molecular Dynamics

It is essential to develop novel zero- and two-dimensional hybrid perovskites to facilitate the development of eco-friendly solar cells. In this study, we investigated the structure and dynamics of [NH₃(CH₂)₅NH₃]CuCl₄ via various characterization techniques. Nuclear magnetic resonance (NMR) results indicated that the crystallographic environments of ¹H in NH₃ and ¹³C on C3, located close to NH₃ at both ends of the cation, were changed, indicating a large structural change of CuCl₆ connected to N–H···Cl. The thermal properties and structural dynamics of the [NH₃(CH₂)_nNH₃] cation in [NH₃(CH₂)_nNH₃]CuCl₄ (n = 2, 3, 4, and 5) crystals were compared using thermogravimetric analysis (TGA) and NMR results for the methylene chain. The ¹H and ¹³C spin-lattice relaxation times (T_1ρ) exhibited similar trends upon the variation of the methylene chain length, with n = 2 exhibiting shorter T_1ρ values than n = 3, 4, and 5. The difference in T_1ρ values was related to the length of the cation, and the shorter chain length (n = 2) exhibited a shorter T_1ρ owing to the one closest to the paramagnetic Cu²⁺ ions.     

Synthesis,characterization, and temperature‐responsive behaviors of novel hybrid amphiphilic block copolymers containing polyhedral oligomeric silsesquioxane

Organic/inorganic hybrid amphiphilic block copolymer poly(methacrylate isobutyl POSS)‐b‐poly(N‐isopropylacrylamide‐co‐oligo(ethylene glycol) methyl ether methacrylate) (PMAPOSS‐b‐P(NIPAM‐co‐OEGMA)) was synthesized via reversible addition–fragmentation chain transfer polymerization. The self‐assembly behavior of this block copolymer in aqueous solution was investigated by dynamic light scattering (DLS) and transmission electron microscopy. The results indicate that the novel block copolymer can self‐assemble into spherical micelles with PMAPOSS segment as the hydrophobic part and P(NIPAM‐co‐OEGMA) segment as the hydrophilic part. The temperature‐responsive characteristics of the assemblies were tested by UV–Vis spectra and DLS. Some factors such as the concentration, molecular weight, and copolymer generation that may affect the cloud point were studied systematically. The results reveal that this copolymer exhibits a sharp and intensive lower critical solution temperature (LCST). The essentially predetermined LCST can be conveniently achieved by adjusting the content of NIPAM or OEGMA domain. In addition, these novel hybrid micelles can undergo an association/disassociation cycle with the heating and cooling of solution and the degree of reversibility displaying a tremendous concentration dependence, as a novel organic/inorganic hybrid material with distinctive virtues can be potentially used in biological and medical fields, especially in drug nanocarriers for targeted therapy. Copyright © 2014 John Wiley & Sons, Ltd.     

锂电池混合动力轮胎吊AFE变换器控制策略研究

针对传统采用不可控AC/DC变换器的混合动力轮胎式起重机系统,直流母线电压泵升导致的柴油发电机空转,造成能量浪费的问题。采用可控的有源前端变换器取代不可控的二极管整流,建立了AFE功率外环电流内环以及电压外环电流内环两种双环控制方法以实现柴油发电机输出功率的高效利用。运用matlab/simulink搭建了仿真模型,分别进行了锂电池混合动力RTG系统重载、轻载、空载下的动态仿真,仿真结果表明,两种双环控制方法均能实现锂电池混合动力RTG系统柴油发电机的恒功率输出,控制系统具有较好的动态性能。     

Fully polarizable QM/MM calculations: An application to the nonbonded iodine–oxygen interaction in dimethyl‐2‐iodobenzoylphosphonate

The compound dimethyl‐2‐iodobenzoylphosphonate is unusual in that it forms well‐ordered crystals that clearly show short iodine‐oxygen interactions in which both the iodine and the oxygen are in their normal oxidation states. These interactions were studied using a new hybrid quantum mechanical–molecular mechanical approach that employs a polarizable molecular mechanics component. The electric field at the molecular mechanics atoms was calculated from a distributed multipole expansion of the wave function; this induced dipoles on the molecular mechanics atoms. The electrostatic potential in a spherical shell around the induced dipoles was reproduced through induced charges on the atomic center and those bonded to it using an analytical (rather than numerical) procedure. The new atomic charges (induced charges plus permanent charges) were then able to interact with the quantum mechanical entity and polarize the wave function. The procedure was iterated to convergence. The calculations show that the iodine atom becomes more positive in the crystal environment (modeled by a chain of three molecules of dimethyl‐2‐iodobenzoylphosphonate). Thus, while the cooperative effects of the crystal environment may not be the only feature stabilizing this unusual interaction, they do play a significant role in reducing the otherwise unfavourable iodine–oxygen monopole–monopole interaction. © 2000 John Wiley & Sons, Inc. J Comput Chem 21: 478–482, 2000     

SYNTHESIS AND CHARACTERIZATION OF NOVEL SOL-GEL DOPED ORGANIC／INORGANIC HYBRID NONLINEAR OPTICAL MATERIALS

4-hydroxy-4 ‘-nitro azobenzene (NHA) and 4-amino-4 ‘-nitro azobenzene (DO3) were prepared respectively from p-nitrophenylamine as a precursor compound. Two kinds of doped organic/inorganic hybrid nonlinear optical (NLO) materials containing NHA and DO3 were synthesized by Sol-Gel process. The preparation and properties of two NLO materials were studied and characterized by FTIR, IH-NMR, UV-VIS, SEM, DSC and SHG measurements. The results show that the maximum doping amounts of NHA and DO3 in two doped hybrid NLO materials are 7.2(wt)% and ll.3(wt)% respectively, and the corresponding second-order NLO coefficients (d33values) are 2.91 ×l0^-3esu and 6.14×10 -8 esu. Two doped NLO materials have relatively good RT stability, after 90 days at RT the d33 values can maintain about 85% of their initial values, but after l0h at 100℃ can only maintain about 50% of their initial values. In this report, the reasons for high-temperature instability of doped materials were discussed, and the possible improvements were also suggested.     

DNA‐Based Hybrid Catalysts for Asymmetric Organic Synthesis

Stereoselective hybrid systems based on metal‐assisted catalysis with a chiral biomacromolecule form an attractive research area for the synthesis of enantiomerically pure compounds. Although various methods are available for this purpose, most rely on the use of enzymes, proteins, or RNA. The application of DNA‐based hybrid catalysts for enantioselective synthesis emerged only a few years ago. DNA‐based hybrid catalysts have been self‐assembled from DNA and a metal complex with a specific ligand through supramolecular or covalent anchoring strategies and have demonstrated high stereoselectivity and rate enhancement in Lewis acid catalyzed reactions, such as Diels–Alder, Michael addition, and Friedel–Crafts reactions. For these reactions, cheap and commercially available salmon testes DNA has generally been used. In this Minireview, we summarize recent developments in the area of asymmetric catalysis with DNA‐based hybrid catalysts.     

Synthesis and Optical Properties of Europium‐Complex‐Doped Inorganic/Organic Hybrid Materials Built from Oxo–Hydroxo Organotin Nano Building Blocks

Hybrid materials doped with novel europium complexes were synthesized using PMMA‐co‐Sn₁₂Clusters (copolymers from oxohydroxo‐organotin dimethacrylate and methylmethacrylate) as the matrix material. Two types of hybrid materials were obtained: the physically doped product, PMMA‐co‐Sn₁₂Cluster/Eu(TTA)₃phen, and the grafted product, PMMA‐co‐Sn₁₂Cluster‐co‐[EuAA(TTA)₂phen] (TTA=2‐thenoyltrifluoroacetone, phen=phenanthroline and AA=acrylic acid). The hybrid materials exhibited characteristic luminescence of the Eu³⁺ ions, and also showed relative especial optical properties compared with samples just using PMMA as the matrix material. The PMMA‐co‐Sn₁₂Cluster matrix exhibited a high physical doping quantity of [Eu(TTA)₃phen], which can be attributed to the special structure of this kind of hybrid material. GPC (gel‐permeation chromatography), TGA (thermogravimetric analysis), SEM, ¹H NMR, ICP (inductively coupled plasma), ¹¹⁹Sn NMR, FTIR, and diffuse reflectance techniques were employed to characterize the structures and properties of these hybrid materials.     

二维手性层结构的无机-有机杂化磷酸镓(1,10-phen)Ga2(HPO4)2F2(H2O)的水热合成与表征

在水热体系中, 制备了二维手性层结构的(1,10-phen)Ga2(HPO4)2F2(H2O)无机-有机杂化磷酸镓化合物(简称JGP-7).用X射线粉末衍射、元素分析、诱导耦合等离子体、红外光谱、热重分析和X射线单晶衍射对其进行了表征.单晶结构分析表明, 该化合物属单斜晶系, P21/c空间群, 晶胞参数a=0.760 4(1) nm, b=2.169 1(4) nm, c=0.995 2(2) nm, β=99.93(3)°, V=1.619 3(3) nm3, μ=3.607 mm-1, Z=4, F(000)=1 120, R1=0.037 5, wR2=0.056 9, GOF=0.986.JGP-7的骨架由四元环组成的Ga(1)-P(1,2)-O一维链与Ga(2)2F4(H2O)2二聚体通过共用桥O原子构成具有4-, 10-元环的层状结构, 无机层状结构间呈现手性对映.这个无机层通过1,10-邻菲罗林配体相互作用形成的π-π堆积扩展为三维超分子结构.     

含倍半硅氧烷的杂化聚合物

从杂化材料的形成方式 ,说明含倍半硅氧烷类杂化材料是基于化学键合作用形成的分子内杂化体系 ,是一类新型高性能的有机_无机杂化材料。介绍了倍半硅氧烷的结构、合成方法及性能特点 ,重点阐述了多面齐聚倍半硅氧烷类杂化聚合物的性能特点及其发展趋势。