Synthesis and Structural Studies of 2,2′-[(2E,5E)-hexane-2,5-diylidenedi-nitrilo]-dibenzenethiol and 2-Hydroxybenzaldehyde (2E,5E)-hexane-2,5-diylidenehydrazone ligands and their Mononuclear Cu(II) and Ni(II) Complexes

Monomeric copper(II) and nickel(II) complexes with tetradentate two new ligands, 2,2′-[(2E,5E)-hexane-2,5-diylidenedi- nitrilo]dibenzenethiol(H₂L) and 2-hydroxybenzaldehyde (2E,5E)-hexane-2,5-diylidenehydrazone(H₂L¹) have been synthesized and characterized by elemental analyses, magnetic moments, molar conductance, ¹H-NMR and ¹³C-NMR, IR, mass spectral studies, theoretical calculations (MM2 and AM1) molecular methods. The mononuclear metal complexes of H₂L and (H₂L¹) were found to have a 1:1 metal:ligand ratio. Elemental analyses, stoichiometric and spectroscopic data of metal complexes indicated that the metal ions were coordinated to the sulphur (-SH) and/or (-OH) oxygen and imine nitrogen atoms (C = N). All of the data obtained from spectral, and molecular mechanics (MM2) or semi empirical calculations (AM1) studies support the structural properties of ligands and its Cu(II) and Ni(II) metal complexes.     

两个含有杂环硫酮的银(Ⅰ)配合物的合成、晶体结构和光谱特性

合成了2个含有杂环硫酮的银(Ⅰ)配合物,[AgBr(PPh₃)₂(BTZT)]₂ (1),[Ag₂Cl₂(PPh₃)₂(BTZT)₂]CH₃OH (2)(PPh₃=三苯基膦;BTZT=苯并噻唑-2-硫酮),并通过红外光谱、X射线单晶衍射、荧光光谱和核磁氢谱进行表征.2个配合物是在含有2-巯基苯并噻唑(MBT)的甲醇与二氯甲烷混合溶液中,AgX(X=Cl,Br)与三苯基膦反应得到的.MBT配体由于存在化学活性基团(-N(H)-C(=S)-),所以可以转化为BTZT配体.结构分析显示有2个相同的分子结构存在于配合物1中,但是它们具有不同的键长和键角.配合物2是一个含有菱形的[Ag₂Cl₂]单元在中心的反转对称二聚体,2个相邻[AgCl(PPh₃)(BTZT)]单元由2个氯原子桥连.     

含双(2-二苯基膦苯基)醚的Ag(Ⅰ)配合物的合成和表征

合成了2个含有双膦配体的Ag(Ⅰ)配合物,分别是[Ag（DPEphos）（dppe）]₂SO₄（1）和[Ag（DPEphos）（SCN）]₂·CH₂Cl₂（2）（DPEphos=双（2-二苯基膦苯基）醚,dppe=双（二苯基膦）乙烷）,并通过红外光谱,核磁氢谱,元素分析,X射线单晶衍射及荧光光谱表征分析。通过热重分析了2个配合物的热稳定性。结构分析表明配合物1具有简单的单核结构,每个Ag和2个膦配体中的4个P原子螯合配位。配合物2具有双核结构,在配合物2中存在微弱的金属与金属间的作用。在Ag₂S₂环中,4个原子相互之间形成的内角之和为360°,形成的环[-Ag-S-Ag-S-]是一个平行四边形。荧光光谱显示配合物中的发射峰主要来源于双膦配体中的π-π^*跃迁。热重分析结果表明,在340℃附近,2个配合物开始分解,具有良好的稳定性。     

B2O3-Bi2O3-ZnO-Al2O3玻璃助烧剂对BaTiO3陶瓷烧结条件、晶体结构和介电性能的影响

通过调节B₂O₃‐Bi₂O₃‐ZnO‐Al₂O₃(BBZA)玻璃的添加量研究其对钛酸钡(BaTiO₃)陶瓷烧结条件、晶体结构和介电性能的影响。结果表明：添加适量的BBZA玻璃能够有效地将BaTiO₃陶瓷烧结温度由1350℃降至950℃,并使其致密化。同时,添加BBZA玻璃后,BaTiO₃的晶体结构随着烧结温度的升高而发生转变(立方相→四方相)。另外,BBZA玻璃的引入使BaTiO₃陶瓷的居里峰得到了有效的抑制和拓宽。陶瓷微观形貌显示,玻璃相均匀分布在BaTiO₃晶粒表面。优化的BaTiO₃陶瓷制备条件如下：BBZA添加量(质量分数)为2.0%,烧结温度为950℃。在该条件下制备的BaTiO₃陶瓷介电常数达到1364,介电损耗低至1.2%。     

Dispersion corrected double high-hybrid and gradient-corrected density functional theory study of light cation–dihydrogen (M+–H2, where M = Li, Na, B and Al) van der Waals complexes

Structure, frequencies, H–H stretching frequency shifts, interaction energy, depth of the potential well and dissociation energy of the light cation–dihydrogen (M⁺–H₂, where M = Li, Na, B, and Al) van der Waals complexes have been studied in detail using dispersion corrected double-hybrid and gradient-corrected density functional methods in conjunction with correlation consistent valence triple-ζ basis set. Equilibrium bond distance and dissociation energy agree very well with the experimental and theoretical values wherever available. The dissociation energies of Li⁺–H₂, B⁺–H₂, Na⁺–H₂, and Al⁺–H₂ van der Waals complexes calculated from the potential energy curves at mPW2PLYP-D/cc-pVTZ level are 4.83, 3.68, 2.42, and 1.25 kcal/mol, respectively, at a distances of 1.95, 2.25, 2.40, and 2.95 Å. Among all these complexes, Al⁺–H₂ complex is comparatively less stable, as their dissociation energy as well as depth of the potential well are smaller compared to others complexes. The symmetry-adapted perturbation theory (SAPT) has been applied to quantify the nature of interactions. The SAPT results show that the contribution of dispersion and induction are significant, although electrostatic dominates.     

Efficient and Convenient Methods for Synthesis of Some Phthalazine Derivatives and Their Evaluation of Cytotoxicity

A systematic study of the reaction of 1,4-dihydrazinophthalazine (DHPH) with 1,3-dicarbonyls [viz., acetylacetone (acac), dibenzoylmethane (bzbz), and 1-benzoylacetone (bzac)] varying the reaction conditions was carried out to obtain the phthalazine derivatives (1–4). One-pot reaction of DHPH with acac led to the formation of two compounds 1 and 2, with various factors such as the presence of the acid or base, amount of the acac, time of reflux, and the temperature. The reaction conditions of DHPH with bzbz or bzac are sort of different to isolate the products 3 and 4, respectively. The derivatives (1–4) have been characterized by elemental analyses, ¹H NMR, and electrospray ionization–mass spectrometry (ESIMS) and the cytotoxic activity of the compounds 1–4 was evaluated on HeLa cell line.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

基于粒子群优化的竞优评析拓展方法及评价引导功效——以TOPSIS模式为例

现有的竞优评析研究主要以线性加权、数据包络分析等线性模型为基础,缺少普适于非线性效用函数的竞优评析研究,限制了竞优评析理论的适用范围与发展空间。本文以TOPSIS效用函数为例,采用PSO优化算法解决非线性个体优势特征识别问题,实现竞优评析理论的拓展。最后,以人力资源管理中的人员业绩评价问题为例给出具体算例,对比验证了所提拓展方法的正确性与有效性;同时,结合计算结果所具有的“极端价值主张”现象,从评价方法的“后效”引导作用的角度,提出了评价方法的“引导功效”概念及其评判标准,供选择评价方法时参考。     

Oriented bipartite graphs and the Goldbach graph

In this paper, we study oriented bipartite graphs. In particular, we introduce “bitransitive” graphs. Several characterizations of bitransitive bitournaments are obtained. We show that bitransitive bitounaments are equivalent to acyclic bitournaments. As applications, we characterize acyclic bitournaments with Hamiltonian paths, determine the number of non-isomorphic acyclic bitournaments of a given order, and solve the graph-isomorphism problem in linear time for acyclic bitournaments. Next, we prove the well-known Caccetta-Häggkvist Conjecture for oriented bipartite graphs in some cases for which it is unsolved, in general, for oriented graphs. We also introduce the concept of undirected as well as oriented “odd-even” graphs. We characterize bipartite graphs and acyclic oriented bipartite graphs in terms of them. In fact, we show that any bipartite graph (acyclic oriented bipartite graph) can be represented by some odd-even graph (oriented odd-even graph). We obtain some conditions for connectedness of odd-even graphs. This study of odd-even graphs and their connectedness is motivated by a special family of odd-even graphs which we call “Goldbach graphs”. We show that the famous Goldbach's conjecture is equivalent to the connectedness of Goldbach graphs. Several other number theoretic conjectures (e.g., the twin prime conjecture) are related to various parameters of Goldbach graphs, motivating us to study the nature of vertex-degrees and independent sets of these graphs. Finally, we observe Hamiltonian properties of some odd-even graphs related to Goldbach graphs for a small number of vertices.