取代脂环烃物理化学性质的拓扑化学研究

为了探讨有机化合物的分子结构与理化性质的关系,作者在以前的工作基础上,基于一阶分子连通性拓扑指数构建了一个信息拓扑指数.将拓扑指数与取代脂环烃系列分子的气态标准生成热、气态标准熵、气态标准生成自由能、沸点、临界温度、临界压力、临界体积、汽化热、密度、热容及表面张力等十一种热力学性质及物理化学性质相关联,用一个通用公式对各类性质进行概括,然后用已有的实验数据与拓扑指数进行回归分析,得到一系列计算各性质的经验公式.回归结果发现,分子的理化性质与拓扑指数有较好的相关性,有5类性质的复相关系数大于0.99.用经验公式对各类性质进行重新计算,其结果与实验值比较符合,用实验值对计算值作图,发现各数据点紧靠对角线,说明误差较小.残差分布呈正态分布.     

多氯联苯的定量结构－性质(活性)关系

多氯联苯(PCBs)是一类重要的持久性环境污染物.首先对所有209个PCB分子进行了HF/6-31G*水平上的结构优化, 在优化结构上获得了分子的表面静电势分布, 并在此基础上对其统计导出的参数进行了计算．其后, 运用多元线性回归方法对PCBs的水溶性、正辛醇/水分配系数、正辛醇/空气分配系数、土壤吸附性、水溶液活度系数、298 K超冷流体蒸汽压、总分子表面积、色谱保留指数、升华焓、蒸发焓、熔融焓、PCB结合芳烃受体活性数据、生物降解度以及生物降解速率参数等理化性质和生物活性与分子的结构参数进行了关联．结果表明:分子静电势参数结合分子表面积和常规的量子化学参数可以很好地用于表达多氯联苯分子理化性质和生物活性与其分子结构间的定量关系．     

一种新的分子拓扑指数及其在QSPR/QSAR研究中的应用

通过引入量子数、键参数,认为分子的性质与其中各原子的电负性、价电子数、成键电子数、价层主量子数及各化学键的键长有关,提出了一种新的分子拓扑指数mAY.采用该拓扑指数对饱和烷烃、烷基苯、烷氧氯硅烷、卤代苯、含氮杂环化合物、碱金属卤化物及卤化锡的性质/活性进行了相关关系的研究.结果表明,mAY与有机物和无机物的性质/活性间具有良好的相关性.     

饱和链烃图特征和热力学性质

本文讨论饱和链烃分子异构化和热力学性质之间的关系.首先利用图论方法引进描写分子支化度的α_N指数,该指数能分辨仅有微小结构差异的饱和链烃分子,给出支化结构的合理描述.在此基础上,得到了利用分子图特征参量计算饱和链烃热力学量(如:沸点、密度、生成焓、原子生成热、折射率和色谱保留指数等)的统一表达式.     

定位对应指数与多氯联苯醚理化性质的构效关系

通过计算多氯联苯醚(PCDEs)所有209种可能分子结构的原子特征值,利用分子图形技术获得了定位对应指数;以106种PCDEs的理化性质实验值为建模样本,由多元回归方法建立了PCDEs的饱和蒸气压(P0L)、水溶解度(SW)和正辛醇,水分配系数(KOW)的定量结构一性质相关模型,相关性良好(r＞0.98),估算的平均误差分别为0.12、0.28和0.09.利用此方程对另外103个未见实验数据报道的多氯联苯醚分子的理化性质进行预测,结果和相同氯原子数的实验平均值较为接近,预测能力优于文献.     

全氟化合物热力学性质的密度泛函理论研究

用密度泛函理论B3LYP方法,在6-31G基组水平上,对12个全氟化合物分子进行了全优化计算,得到其分子零点振动能EZPV、热能校正值Eth、恒容热容CVΦ、标准熵SΦ以及配分函数lgQ等热力学参数,并计算了这些分子的电性拓扑状态指数Em.通过最佳变量子集回归建立了电性拓扑状态指数与热力学参数之间的QSPR模型,模型的相关系数R2分别为1.000,1.000,1.000,0.999和1.000,采用逐一剔除法得到的交叉验证相关系数R2cv分别为0.999,1.000,1.000,0.999和1.000,利用建构的数学模型得到热力学性质的相对平均误差分别为0.43%,0.41%,0.46%,0.41%和0.71%.从方程可以看出,F原子取代基数量是影响全氟化合物分子热力学参数大小的主要因素,检验证明所建模型具有良好的稳定性和预测能力.     

用于饱和链烃类化合物的结构/性质相关性研究的一种新的拓扑指数

分子的结构决定分子的性质 ,从分子结构提炼出的结构信息进行数值化即得到分子拓扑指数。用拓扑指数来进行定量结构 活性相关性(ＱＳＡＲ)以及定量结构 性质相关性 (ＱＳＰＲ)研究是目前非常活跃的领域。到目前为止 ,已相继提出1 2 0多种拓扑指数[1] 。利用这些拓扑指数来讨论饱和链烃类化合物的性质已经得到了许多有益的结果[2 ] 。本文利用距离矩阵和邻接矩阵 ,提出了一种新的拓扑指数Ｚｈ,对饱和链烃类化合物的性质进行预测和预报 ,结果表明 ,这种拓扑指数具有良好的结构选择性和性质相关性。1　方法以 2 甲基丁烷为例 ,其隐氢图为 :其…     

基于分子表面静电势参数研究多环芳烃化合物的定量结构-性质关系

对一系列多环芳烃分子进行了HF/6-31G^*水平上的结构优化,在优化结构上进行了分子静电势及其导出参数的计算.运用多元线性回归方法对多环芳烃的沸点、色谱保留指数、水溶性、正辛醇/水分配系数、正辛醇/空气分配系数、土壤吸附性、亨利系数以及生物富集因子等理化性质与分子的结构参数进行了关联.结果表明:分子空间和表面最负的静电势(V_min和V_s,min)、分子表面正的静电势和负的静电势的求和(∑V_s⁺和∑V_s^-)、表面静电势的平衡参数(ν)加上分子的体积可以很好地用于表达多环芳烃分子理化性质与其分子结构间的定量关系.     

原子配分参数、配分连接性指数及其应用

结构决定性质，性质反映结构，这是化学、生物学等学科的一条基本规律。因此，分子的微观结构与性质之间存在着密切关系。物质的理化性质、生物活性等数据的获取，迄今主要来自于实验。如能建立结构与性能之间的数量关系用以估算与预测分子的性质，这无疑是一项十分有意义的工作。拓扑指数法以其计算简单、准确性高、应用范围广而在上述领域中发挥重要作用犤１～４犦。拓扑指数是对分子结构进行的定量描述，使分子之间的结构差异定量化。自Wiener提出第一个拓扑指数（W）犤５犦以来，迄今已有２００余种拓扑指数问世。其中一部分能够有效地…     

Lennard-Jones分子基态结构的反常拓扑性质

根据遗传算法的基本原理，建立了一种优化分子几何结构的理论计算程序，对用Lennard-Jones势描述的惰性气体分子LJ38的结构进行了优化计算，并进一步计算了其结构的拓扑指数．结果显示出LJ38分子基态结构具有奇特的和文献报等不一致的反常拓扑性质．     

Mechanical Properties of Gel-Derived Materials

The mechanical behaviour of xerogels and aerogels is generally described in terms of brittle and elastic materials, like glasses or ceramics. The main difference compared to silica glass is the order of magnitude of the elastic and rupture moduli which are 10⁴ times lower. However, if this analogy is pertinent when gels are under a tension stress (bending test) they exhibit a more complicated response when the structure is submitted to a compressive stress. The network is linearly elastic under small strains, then exhibits yield followed by densification and plastic hardening. As a consequence of the plastic shrinkage it is possible to densify and stiffen the gel at room temperature. These opposite behaviours (elastic and plastic) are surprisingly related to the same two kinds of gel features: the silanol content and the pore volume. Both elastic modulus and plastic shrinkage depend strongly on the volume fraction of pores and on the condensation reaction between silanols. On the mechanical point of view (rupture modulus and toughness), it is shown that pores and silanols play also an important role. Pores can be considered as flaws in the terms of fracture mechanics and the flaw size, calculated from rupture strength and toughness is related to the pore size distribution. Different kinds of gels structure (fractal or not fractal) have been synthesized by a control of the different steps of transformation such as sintering and plastic compaction. The relationships between structural and the elastic properties are discussed in terms of the percolation theory and fractal structure.     

紫外光固化PDLC膜性能的温度效应

考察了紫外光固化PDLC膜的电光性能及其温度依赖性,阐述了其作为显示器件的工作稳定性。指出确定PDLC工作温度范围的方法,对PDLC膜中液晶相的N-I转变行为及其与膜的内部结构的关系进行了讨论。     

Mechanical and Morphological Properties of Bio-Phenolic/Epoxy Polymer Blends

Polymer blends is a well-established and suitable method to produced new polymeric materials as compared to synthesis of a new polymer. The combination of two different types of polymers will produce a new and unique material, which has the attribute of both polymers. The aim of this work is to analyze mechanical and morphological properties of bio-phenolic/epoxy polymer blends to find the best formulation for future study. Bio-phenolic/epoxy polymer blends were fabricated using the hand lay-up method at different loading of bio-phenolic (5 wt%, 10 wt%, 15 wt%, 20 wt%, and 25 wt%) in the epoxy matrix whereas neat bio-phenolic and epoxy samples were also fabricated for comparison. Results indicated that mechanical properties were improved for bio-phenolic/epoxy polymer blends compared to neat epoxy and phenolic. In addition, there is no sign of phase separation in polymer blends. The highest tensile, flexural, and impact strength was shown by P-20(biophenolic-20 wt% and Epoxy-80 wt%) whereas P-25 (biophenolic-25 wt% and Epoxy-75 wt%) has the highest tensile and flexural modulus. Based on the finding, it is concluded that P-20 shows better overall mechanical properties among the polymer blends. Based on this finding, the bio-phenolic/epoxy blend with 20 wt% will be used for further study on flax-reinforced bio-phenolic/epoxy polymer blends.     

超微电极上聚苯胺的电化学性质研究

本文探讨了盐酸介质中，聚苯胺在超微电极上的伏安性质，峰电流（ｉｐ）ａ与聚合电量、扫描速率等关系，在Ｑｐ较小时，具有薄膜电极特性，Ｑｐ很大时峰电流受扩散控制。     

Preparation and Properties of Novel Cyclophosphazenes Containing Cyanato Groups

Abstract

Novel cyclotriphosphazenes containing cyanato group (PZCN) derivatives were synthesized by a substitution reaction of 4-hydroxyphenoxycyclotriphosphazenes and cyanogen bromide (BrCN) in the presence of triethylamine (TEA). The PZCNs were characterized by FT-IR, liquid chromatography–mass spectrometry (LC-MS), ¹H NMR, ¹³C NMR, and ³¹P NMR spectroscopy. Curing reactions of the PZCNs were evaluated by FT-IR spectroscopy, thermogravimetry/differential thermal analysis (TG/DTA), and differential scanning, calorimetry (DSC). The PZCNs exhibited an exothermic peak due to curing within the temperature range of 140–300°C by DSC. The PZCNs were completely cured at 220°C. The cured PZCNs exhibited high thermal stability up to 350°C, a high char-forming capability, and electrical properties, such as dielectric constants (Dks) between 2.68 and 2.87, and dissipation factors (Dfs) between 0.008 and 0.013 at 1 MHz.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Scaling Properties and Structure of Aerogels

Young’s modulus as well as solid thermal and electrical conductivity of aerogels have been observed to scale with density. No quantitative explanations were available up to now for these experimental findings. To establish a quantitive relationship between morphological and topological features of fractal gel networks, a simulation procedure is introduced that allows to produce three-dimensional gel structures, from which two important parameters can be extracted: i) the fraction α of interconnected mass of the gel network and ii) the ratio γ of Pythagorean distance to minimum path length on the gel backbone. Surprisingly the product αγ, which enters important macroscopic parameters such as elasticity or solid thermal (and electrical) conductivity, was found to scale with an exponent that is only a function of the mass fractal dimensionD. Also, an analytical relation between modulus and conductivity can be derived.     

Effect of Structure on Surfactant Properties

The surface tension and foaming properties of sodium oleate were altered by adding a large and electronegative moiety bromine, to its unsaturation. These properties were measured and compared to the original oleic soap. It was found that sodium oleate has a lower CMC than both of the brominated surfactants. The bromine moiety slows down the rate of adsorption with the doubly brominated surfactant being the slowest. Foamability of the brominated analogues were not affected, however its foam were found to be less stable. Bromination also caused the coalescence and bursting of large bubbles.     

含Silole共轭聚合物的光电性能

Silole是一类含硅杂环戊二烯,近年来,由于其独特的结构特性、分子的可设计性及多样性,在光电领域得到越来越多研究者们的关注。某些silole小分子在有机发光二极管中用作发光层和电子传输层有出色的表现,但近来对含silole聚合物的研究也颇受重视,在聚集态诱导发光、化学传感器、聚合物发光二极管、聚合物太阳能电池、场效应晶体管中的应用相继有报道。因此silole是一类很有潜力的构筑光电功能材料的杂环化合物。本文根据其母体结构的不同对含silole的聚合物光电性能研究进展进行了综述。     

磷系阻燃共聚酯的结构与性能

采用磷系阻燃剂2-羧乙基苯基次磷酸（CEPPA）作为第3单体,通过聚合反应制备了含磷的阻燃共聚酯。采用核磁共振、DSC、元素分析和极限氧指数仪表征阻燃共聚酯的化学组成、序列分布、结晶性能、磷含量和极限氧指数。结果表明：大部分CEPPA单元以无规分布的形式共聚到聚酯分子链中,小部分CEPPA单元以短嵌段的形式共聚在聚酯分子链中,且随着阻燃剂含量增加,无规系数变小。由于分子链的规整性下降,与聚对苯二甲酸乙二酯（PET）相比,阻燃共聚酯的Tg和Tm下降,结晶度减小。随阻燃剂含量的增加,极限氧指数值增加,当阻燃共聚酯中的磷含量达到9．08mg／g时,极限氧指数值达到33％以上。     

一种新型功能性显影促进剂的照相性能和抗老化性研究

研究了新型功能性显影促进剂照相性能与作用机理.照相性能试验结果表明:显影促进剂M能明显提高感光度而且具有良好的抗老化性能;染料吸收光谱的结果表明:它的使用不影响主成色剂成色染料的吸收光谱.