金属有机配合物晶体中二次谐波基因的结构优化及其验证

提出了二次谐波效应的二次极化率矢量模型并介绍该模型的要点，该类型晶体材料的电子结构和分子结构的优化以及综合反映晶体倍频效应的物理量－二次极化强度方均值Ｐ＾２（２ω），为探索和研制该类型的晶体材料提供一定的线索。     

金属有机配合物晶体中二次谐波基团的结构优化及其验证

提出了二次谐波效应的二次极化率矢量模型并介绍该模型的要点、该类型晶体材料的电子结构和分子结构的优化以及综合反映晶体倍频效应的物理量－二次极化强度方均值Ｐ~２（２ω），为探索和研制该类型的晶体材料提供一定的线索。     

新磺酰脲类化合物的合成、结构及构效关系研究(Ⅴ)─—N-[2-(4-乙基)三嗪基]-2-硝基-苯磺酰脲的晶体及分子结构

为了进一步研究超高效、低毒除草剂磺酸豚类化合物的分子结构和构象对活性的影响，特别是考察其分子中杂环部分为三酸基时的结构与活性关系，我们研究了N－［2－（今乙基）三埃基」－2一硝基一苯横卧脉的晶体及分子结构，比较了它与横卧腺分子中杂环为喀院环的构象差异．1样品的合成与表征标题化合物的合成反应路线如下［‘”j：产物1的熔点为182～183℃．元素分析（C；。H；则对。S，％）实验值：C41．11，H3．37，N24．24；计算值：C40．90，H3．67，N23．85IR，P／cm’：3411（N－H），1724（C—O及一NHCONH），13662，1163．5…     

一水甲酸锂晶体二阶非线性光学系数的理论计算

采用有限场方法和含时耦合微扰方法,在6-31+G*基组水平上并考虑了电子相关效应和色散效应的影响,计算了一水甲酸锂晶体的宏观二阶非线性光学极化率和二阶非线性光学系数。其中非线性光学系数d31和d32与Roberts报道的相符,而另一个系数d33则比文献值大。计算结果还表明,在非共振情况下,电子相关效应对非线性光学极化率的影响远远超过了色散效应,同时表明Roberts报道的非线性光学系数比Singh等人报道的更为合理。     

含噻吩环的新推—拉型多环电光聚合物中间体的三阶非线性？…

以ＩＮＤＯ／ＳＣＩＯ方法的基础，利用完全态求和（ＳＯＳ）公式，计算了一系列新推－拉型多环电光聚合物间体的三阶非线性光学系数γ（－ω，ω，－ω，ω）、γ（０；０，０，０），研究了γ与分子骨架，给受取代基和噻吩环数目（共轭分子链长的关系）及其与外频率的关系，表明在链不十分长时，γ与链长的２．６９次方成正比。     

溶致变色法测定BMC和MMONS的分子二阶极化率

1引言分子二阶极化率是对倍频材料进行分子设计和优化筛选的重要参量，因而对它的测量也是十分重要的．用直接测量的“电场诱导二次谐波产生（EFISH）”法需要昂贵的设备，在普通实验室难以普及．近年来人们推出了简便易行的溶致变色法测定分子二阶极化率，可得出与EFISH法相平行的结果．本文采用这种方法测定了BMC（4-溴-4’-甲氧基查耳酮）和MMONS（3-甲基-4-甲氧基-4’-硝基二苯乙烯）的分子二阶极化率，并根据有关晶体二阶非线性光学数据和CNDO／S-CI方法结合微扰理论分别计算了它们的β值，得出了与溶致变色法基本一致的结果…     

锂掺杂胺化物中氮原子配位数效应对结构和非线性光学性质的影响

采用MP2／6—311＋＋G（d,p）方法得到了含有不同氮原子配位数的系列锂掺杂胺化物的几何结构,并使用MP2／6．311＋＋G（2d,p）方法计算了该系列的非线性光学性质．结果表明：相对于未掺杂体系,锂掺杂极大地增加了体系的一阶超极化率（β0）,其中1的β0值是掺杂前的3238倍;体系的风随着氮原子配位数的增加而显著增加,具有3个配位氮原子的1的风值达到2．8×10^5a．u．另外,频率依赖的一阶超极化率（β（-ω;ω,0）和β（-2ω;ω,0））也表现了同样的趋势．     

基态Hse分子及Hsex(x=+1,-1) 离子的量子力学计算

用原子-分子反应静力学原理推导出了HSe分子、HSe^x（x=＋1，-1）离子的基态电子状态及其离解极限．在cc—pVDZ水平基础上，用B3LYP方法计算了它们的平衡核间距Re和离解能De．并在计算出来的一系列单点势能基础上，用正规方程组拟合Murrell—Sorbie（M—S）势能函数，得到相应态的解析势能函数，由此计算对应的光谱参数（Be，αe，ωe，ωe，χe）和力学性质，计算结果表明HSe分子、HSe^x（x=＋1，-1）离子可稳定存在．     

应用分子图形学、分子力学、量子化学及静电势研究农药分子结构与性能关系(X)──磺酰脲分子内旋转通道的分子力学研究

磺酞豚分子是一类极其重要的低毒超高效除草剂，有着十分重要的用途．研究分子的空间结构对于了解分子的构效关系十分重要．最近，我们测定的一系列分子的晶体结构［‘－’1表明，分子1、2、3晶体结构的空间群分别为PZ；儿、Pz、Pz，说明晶体中分别有对称元素（对称面或者对称中心），分子以对映体的形式存在于晶体中．由于磺酸豚分子本身不存在手性原子，由此推断磺酷服分子在晶体中存在的对映异构体是由内旋转阻碍产生的，因而应是构象异构体．本项研究工作的目的是应用分子力学方法，计算阻碍内旋转的能垒，从而找出分子内旋转时的最低…     

白光发射超分子水凝胶的构筑和发光性能研究

具有白光发射性质且发光可调的超分子水凝胶在发光材料和荧光检测领域具有广泛的应用前景.采用双（2-氨基丙基醚）聚丙二醇（PPG-NH²）链穿线带有正电荷的6-乙二胺修饰β-环糊精构成准轮烷,进而与锂皂石作用构筑了超分子水凝胶,并通过流变、zeta电势和扫描电镜等手段对凝胶性质进行了表征.当将扭曲分子内电荷转移（TICT）型的有机染料分子硫黄素T（ThT）和碘化4-[4-（二甲基氨基）苯乙烯基]-1-甲基吡啶鎓（DASPI）引入到水凝胶中,这两种有机染料能够在凝胶相中发生荧光共振能量转移（FRET）,从而产生包括白光在内的不同颜色的荧光发射.本研究为水基超分子发光软材料提供了一种新的构筑方法.     

Thermal and Spectroscopic Study of Dehydration of Lithium Formate Monohydrate Single-crystals

Differential scanning calorimetry (DSC) and thermogravimetric analysis (TG) of lithium formate monohydrate (LiHCOO·H₂O) were performed in the temperature range 300–700 K. The DSC/TG measurements show that the dehydration process to anhydrous lithium formate (LiHCOO) is complex and occurs in two stages. The data are correlated to the structure and to the arrangement of the molecules in the crystal, including the hydrogen-bonding. Infrared transmittance and Raman spectra of this crystal are reported and commented on. This revised version was published online in July 2006 with corrections to the Cover Date.     

Experimental study and Monte-Carlo simulation of the nucleation and growth processes during the dehydration of Li2SO4.H2O single crystals

A kinetic model for the dehydration of lithium sulfate monohydrate is proposed in order to account for experimental data obtained on single crystals by thermogravimetry at 80 degrees C under fixed water vapour pressure, and by optical microscopy. This model is based on the assumptions of Mampel's model, the nucleation takes place randomly at the surface of the solid and is followed by isotropic growth toward the centre of the crystal. Calculated rates dalpha/dt are obtained by means of Monte-Carlo simulations and compared to the experimental ones, which leads to the determination of two kinetic constants: the areic frequency of nucleation (in number of nuclei m(-2) s(-1)) and the areic reactivity of growth (in mol m(-2) s(-1)).     

甲酸双氧铀的红外多光子离解

本文研究了固相甲酸双氧铀[UO_2(HCOO)_2·H_2O]在TEA CO_2激光作用下的红外多光子离解。测得其中间产物为碱式甲酸双氧铀[UO_2(OH)(HCOO)·H_2O],最终的固体产物主要是八氧化三铀[U_3O_8];并提出了该反应模型。     

Dehydration of lithium iodide crystal hydrate in vacuum

Dehydration of the LiI · 3H₂O crystal hydrate in vacuum has been investigated at 20–25°C. The decomposition of the LiI · 3H₂O crystal hydrate in vacuum proceeds to monohydrate. During heating of lithium iodide monohydrate, evolution of water vapor is observed at 30–100 and 100–170°C. Above 200°C, evolution of molecular oxygen is observed, possibly, because of the decomposition of lithium peroxide that is formed in side reactions during the decomposition of lithium iodide crystal hydrate.     

Synthesis, spectral, optical and thermal studies of 1-methyl-2,6-dimethyl-4-hydroxypyridinium chloride monohydrate and bromide monohydrate

Semiorganic 1-methyl-2,6-dimethyl-4-hydroxypyridinium chloride monohydrate (MDMPCl.H(2)O) and bromide monohydrate (MDMPBr.H(2)O) salts have been synthesized. Single crystals of MDMPCl.H(2)O and MDMPBr.H(2)O were grown by the slow evaporation method from aqueous solution at constant temperatures 30 and 32 degrees C respectively. The grown crystals were characterized by elemental analysis, FT-IR and FT-NMR techniques and their molecular structures were elucidated. Thermogravimetric, differential thermal analyses and differential scanning calorimetry reveal the presence of water molecules in the crystal lattices and thermal stabilities. Optical transmittance windows in aqueous solution were found as 300-1100 nm using UV-vis-NIR spectrophotometer.     

Vibrational spectroscopic analysis of cytosine monohydrate and its copper(II) complex

Single crystals of cytosine monohydrate and its copper(II) complex were grown by slow evaporation in an aqueous solution at room temperature. The solubility studies were carried out at different temperatures in deionized water. Cytosine monohydrate and the copper(II) complex of cytosine were characterized by recording IR, Raman and UV spectra. The various vibrational modes of the crystals have been classified using factor group and site group analysis. Vibrational assignments were proposed for both the systems based on the spectral investigations.     

EPR study of gamma irradiated N-methyl taurine (C3H9NO3S) and sodium hydrogen sulphate monohydrate (NaHSO3·H2O) single crystals

EPR study of gamma irradiated C(3)H(9)NO(3)S and NaHSO(3).H(2)O single crystals have been carried out at room temperature. There is one site for the radicals in C(3)H(9)NO(3)S and two magnetically distinct sites for the radicals in NaHSO(3). The observed lines in the EPR spectra have been attributed to the species of SO(3)(-) and RH radicals for N-methyl taurine, and to the SO(3)(-) and OH radicals for sodium hydrogen sulfate monohydrate single crystals. The principal values of the g for SO(3)(-), the hyperfine values of RH and OH proton splitting have been calculated and discussed.     

Synthesis, X-ray and neutron diffraction characterization, and ionic conduction properties of a new oxothiomolybdate Li3[Mo8S8O8(OH)8[HWO5(H2O)]] x 18H2O

The new oxothiomolybdate anion [Mo8S8O8(OH)8[HWO5(H2O)]]3- (denoted HMo8W3-) has been synthesized in aqueous solution by an acido-basic condensation reaction. Four (Mo(V)2S2O2) building blocks are connected through hydroxo bridges around a central [W(VI)O6] octahedron. X-ray and neutron diffraction studies have been performed on single crystals of the lithium salt Li3[Mo8S8O8(OH)8[HWO5(H2O)]] x 18H2O (Li3HMo8W x 18H2O) in an aqueous grown from HMo8W3- solution of LiCl (1 M). The neutron diffraction experiment enabled us to locate both the protons and the lithium ions. In the structure of Li3HMo8W x 18H20, ring-shaped anions interleaved by a cluster of disordered hydrogen-bonded water molecules stack on top of each other along lithium pillars. The lithium columns are formed by alternating edge-sharing octahedra and tetrahedra, with one lithium site in four being totally vacant. Ionic conductivity measurements on pressed pellets have shown that Li3HMo8W x 18H2O is a good ionic conductor at room temperature (sigma = 10(-5) S cm(-1)), but the ionic conductivity on single crystals is smaller by two orders of magnitude and is isotropic; this suggests the main path of conduction involves surface protons rather than lithium ions of the bulk.     

Kinetics of electron tunneling stimulated by mobility of lithium cations in lithium gadolinium borate crystals

The kinetics of electron tunneling between electron and hole sites, stimulated by mobility of lithium cations in lithium gadolinium orthoborate (Li₆Gd(BO₃)₃) crystals has been studied. A mathematical model has been proposed to describe the kinetics in the wide time interval of 10⁻⁸–100 s after pulsed irradiation. The calculation results have been compared with experimental data on the decay kinetics of transient optical absorption (TOA) in Li₆Gd(BO₃)₃ crystals in the visible and UV spectral regions. The nature of radiation defects responsible for TOA is discussed, as well as the dependence of the TOA kinetics on temperature, excitation power, and other experimental conditions.