Two-dimensional like conjugated copolymers for high efficiency bulk-heterojunction solar cell application:Band gap and energy level engineering

Three two-dimensional like conjugated copolymers PFSDCN,PFSDTA and PFSDCNIO,which consist of alternating fluorene and triphenylamine main chain,and different pendant acceptor groups (malononitrile,1,3-diethtyl-2-thiobarbituric acid and 2-(1,2-dihydro-1-oxoinden-3-ylidene)malononitrile) with thiophene as π-bridge,have been designed,synthesized and characterized.The structure-property relationships of the two-dimensional like conjugated copolymers were systematically investigated.The absorption spectra,band g...     

New complex of Zn(II) with 3,4,5-trimethoxybenzoate and 2-methylimidazolyl: Synthesis,structure, and luminescence properties

A new zinc(II) complex Zn(TMB)₂(2-MIM)(H₂O)₂ (I), where HTMB is 3,4,5-trimethoxybenzoic acid, 2-MIM is 2-methylimidazole, was synthesized and characterized by Powder X-ray diffraction, FT-IR and photoluminescence spectrum. The complex crystallizes in the monoclinic crystal system (space group C2/c) with the unit cell parameters: a = 18.104(9), b = 8.509(4), c = 17.688(9) Å, β = 103.185(9)°, Z = 4, R ₁ = 0.0740 and wR ₂ = 0.1790. At room temperature the photoluminescence spectrum of complex I in the solid state exhibits maximum excitation at 314 nm and maximum emission at 337 nm.     

Hydrothermal synthesis, structures, and luminescent properties of zinc(II) and cadmium(II) phosphonates with a 3D framework structure using terephthalate as second linkers

By introduction of 1,4-benzenedicarboxylic acid as a second organic ligand, two new divalent metal(II) phosphonates with a 3D framework structure, namely, [Zn(HL1)(bdc)(0.5)] (1) and [Cd(1.5)(HL2)(bdc)(0.5)] (2) (H(2)L1 = H(2)O(3)PCH(NH(2))C(6)H(5), H(3)L2 = H(2)O(3)PCH(2)-NC(5)H(9)-COOH, H(2)bdc = HOOCC(6)H(4)COOH), have been synthesized under hydrothermal conditions. The two compounds show three-dimensional (3D) framework structure with infinite two-dimensional (2D) networks pillared by H(2)bdc. For compound 1, the {ZnO(4)} polyhedra are interconnected by phosphonate groups into a 2D layer, and the adjacent layers are further cross-linked via the bdc(2-) anions to generate a three-dimensional framework structure with two types of channel system along the c-axis. A notable feature of compound 1 is the presence of alternate left- and right-handed helical chains in the structure. In compound 2, the inorganic chains, composed of {Cd(1)O(7)}, {Cd(2)O(4)} and {CPO(3)} polyhedra, are linked by HL2(2-) ligands to form a double layer structure in the ab plane, and the adjacent layers are further linked by the bdc(2-) anions to form a 3D framework structure with one-dimensional channel systems along the a-axis. Luminescence properties of compounds 1 and 2 have also been studied.     

Iron(II) complexes with functionalized amine-pyrazolyl tripodal ligands in the cross-coupling of aryl Grignard with alkyl halides

Structurally distinctive Fe(II) complexes with furan, thiophene and pyridine functionalized amine-pyrazolyl tripodal hybrid ligands have been synthesized and crystallographically characterized. The tether substituent at the central amine plays an active role in determining the coordination mode of the ligand and the metal geometry. All complexes are catalytically active towards cross-coupling of aryl Grignard reagents with primary and secondary alkyl halides with β-hydrogen under ambient conditions. ESI-MS spectra analysis revealed the ligand-stabilised Fe(II) and Mg(II) species.     

A short and highly efficient synthesis of L-ristosamine and L-epi-daunosamine glycosides

A highly efficient synthesis of L-ristosamine and L-epi-daunosamine glycosides via BF(3)·OEt(2) promoted tandem hydroamination/glycosylation of 3,4-di-O-acetyl-6-deoxy-L-glucal and L-galactal has been developed. The new method proceeds in a completely stereocontrolled manner within a short reaction time. Preparation of a library of L-ristosamine and L-epi-daunosamine glycosides with potential biochemical applications, by varying each component, exemplified the generality of the reaction.     

Palladium-catalyzed oxidative C-H bond coupling of steered acetanilides and aldehydes: a facile access to ortho-acylacetanilides

A palladium-catalyzed oxidative C-H bond functionalization/ortho-acylation of acetanilides using easily accessible aldehyde as the acyl source is described. In the presence of a Pd(TFA)(2) catalyst and tert-butylhydroperoxide at 90 °C in general, an array of ortho-acylacetanilides can be afforded in good yields.     

Nanoscale polyoxometalate‐based inorganic/organic hybrids

The latest advances in the area of polyoxometalate (POM)‐based inorganic/organic hybrid materials prepared by self‐assembly, covalent modification, and supramolecular interactions are presented. This Review is composed of five sections and documents the effect of organic cations on the formation of novel POMs, surfactant encapsulated POM‐based hybrids, polymeric POM/organic hybrid materials, POMs‐containing ionic crystals, and covalently functionalized POMs. In addition to their role in the charge‐balancing, of anionic POMs, the crucial role of organic cations in the formation and functionalization of POM‐based hybrid materials is discussed. DOI 10.1002/tcr.201100002     

Limit behavior of the global solutions to the Degasperis-Procesi-type equation

In this paper, we study the Degasperis-Procesi equation with a physically perturbation term—a linear dispersion. Based on the global existence result, we show that the solution of the Degasperis-Procesi equation with linear dispersion tends to the solution of the corresponding Degasperis-Procesi equation as the dispersive parameter goes to zero. Moreover, we prove that smooth solutions of the equation have finite propagation speed: they will have compact support if its initial data has this property.     

带有摄动的随机非线性系统的自适应神经网络控制

针对一类带有摄动的随机严格反馈非线性系统,引入积分型Lyapunov函数,利用神经网络的逼近能力,后推设计方法以及Young's不等式,构造出一类简单有效的自适应神经网络状态反馈控制器,在一定条件下,通过Lyapunov方法,证明了闭环系统的所有信号在二阶或四阶矩意义下半全局一致终结有界.仿真结果验证了所提控制方案的有效性.     

具有垂直传染且总人口在变化的SIRS传染病模型的渐近分析

讨论了具有垂直传染且总人口在变化的连续预防接种SIRS传染病模型,给出了基本再生数R_0的表达式,并利用广义Bendixson-Dulac函数方法证明了无病平衡点和地方病平衡点的全局稳定性.