金配合物[Au（C=C-4-LNO2）（PPh3）二阶非线性光学性质的理论研究

用含时密度泛函理论组合态求和方法研究实验合成的金配合物[Au（C≡C-4-LNO2）（PPh3），L=-C6H4（1），-C5H3N（2）]和自行设计的金配合物[Au（C≡C-4-CdH：N2NO2）（PPh3）L=-C4H2N2]（3）的非线性光学性质．计算结果表明，3个配合物的二阶非线性性质变化规律为β1〈β2〈β3，与芳香性的变化规律正好相反．3个配合物的频率色散理论计算结果与实验观测值不符，暗示着晶体合成时的晶胞排列方式是影响体系宏观NLO性质的关键因素之一．     

金配合物[Au(C≡C-4-LNO2)(PPh3)二阶非线性光学性质的理论研究

用含时密度泛函理论组合态求和方法研究实验合成的金配合物[Au(C≡C-4-LNO2)(PPh3),L=—C6H4(1),—C5H3N(2)]和自行设计的金配合物[Au(C≡C-4-C4H2N2NO2)(PPh3)L=—C4H2N2](3)的非线性光学性质.计算结果表明,3个配合物的二阶非线性性质变化规律为β1<β2<β3,与芳香性的变化规律正好相反.3个配合物的频率色散理论计算结果与实验观测值不符,暗示着晶体合成时的晶胞排列方式是影响体系宏观NLO性质的关键因素之一.     

氮化硅新相P6和P6＇的理论研究：一种研究陶瓷材料的新工具

在原子尺度上构建模型,采用密度泛函理论结合准谐波近似研究了氮化硅新相（P6和P6＇相）的点阵常数、弹性常数和弹性模量. 并使用β-Si3N4作基准材料来测试计算结果的准确性. 研究发现β-Si3N4的晶胞常数和弹性常数与实验值吻合相当好. 研究了P6和P6＇相在30～55 GPa的各向异性因子、脆性和力学稳定性,结果表明两相属于金属性和脆性材料,且晶体的脆性和各向异性都随着压强的升高而增大. β相在40 GPa和300 K时会转变成P6＇相. 当压强继续升高到53．2GPa时,P6＇相又转化成δ相．同时研究了氮化硅的热容、体积和体模量等性质随温度的变化规律．     

基于非金属掺杂g-C3N4的均匀B-C-N三相单层

基于第一性原理方法计算,通过在g-C3N4中掺杂C、B和N原子,预测了四种元素均匀分布的B-C-N三元单层材料,除了B4-C3N4单层材料是一个具有1.18eV带隙的半导体,其余三种C-B-N三元单层材料都是金属材料,其中,B3C-C3N4是铁磁金金属,其净磁矩为0.57μB/原胞,可用于构建自旋电子器件材料,计算的形成能显示B-C-N三元体系具有较高的热稳定性。     

2-(4′-正丙基苯)咪唑并[2,1-a]异喹啉的晶体结构

本文测定了新型抗早孕药物2-(4′-正丙基苯)咪唑并[2,1-a]异喹啉的晶体结构.该化合物分子式为C20H18N2,Mr = 286.38,晶体属单斜晶系,空间群为P21/n,晶胞参数为a = 7.2177(1),b = 7.8036(2),c = 27.429(1) A,β＝ 90.976(3)°,V = 1544.67(8)A3,Z = 4,Dc = 1.231 g/cm3,F(000) = 608.00,μ(Mo-Kα)=0.073mm-1,R = 0.0560,wR = 0.1440,获得25986个衍射点,其中独立衍射点3795个.在分子结构中,苯环(C(1)-C(6))与环(N(1),C(1)-C(9))以及咪唑环共平面,该平面与苯环(C(12)-C(17)所在平面的夹角为10.014°.     

Synthesis,Crystal Structure and Herbicidal Activity of O,O＇-Diethyl-N-[2-（5,7-dimethyl-[1,2,4]triazolo[1,5-a]pyrimidin-2-yloxy）-benzoxyl]-1-amino-benzyl phosphonate

The crystal structure of the title compound (C25H28N5O5P,Mr=509.49) has been determined by single-crystal X-ray diffraction.The crystal is of monoclinic,space group P21/c with a=13.0726(4),b=13.4513(4),c=15.103(1),β=93.650(1)°,V=2650.29(14)3,Z=4,Dc= 1.277 g/cm3,F(000)=1072,μ(MoKα)=0.147 mm-1,the final R=0.0748 and wR=0.1956 for 3186 observed reflections (I 2σ(I)).The fused triazolopyrimidine system ring is coplanar,the dihedral angles between the triazolopyrimidine and C(1)-C(3)-C(5) phenyl,the triazolopyrimidine and C(17)-C(19)-C(21) phenyl,and the two phenyl rings are 66.87,58.79 and 80.11o,respectively.Intramolecular N(5)-H(5A)…O(3) and intermolecular C(2)-H(2)…N(4),C(18)-H(18)…O(3),C(19)-H(19)…O(2) and C(24)-H(24C)…N(4) hydrogen bonds together with C-H…π interactions contribute to the stability of the structure and result in a three-dimensional framework.The preliminary bioassay indicates that the title compound exhibits moderate herbicidal activity against dicotyledonous plants (Brassica campestris L) at the concentration of 100 mg/L.     

Cp_2M_2(μ-B_4N_4H_8)(M=V,Cr,Mn,Fe)金属多重键成键性质的理论研究

对金属多重键配合物Cp2M2(μ-B4N4H8)(M=V,Cr,Mn,Fe)的结构和成键进行了理论研究,并与Cp2M2(μ-C8H8)进行对比.计算结果表明,在Cp2M2(μ-B4N4H8)基态构型中,B4N4H8配体均以硼为桥原子,金属原子的配位数均为5.其中,Cp2M2(μ-B4N4H8)(M=V,Cr,Mn)基态的结构和成键都与Cp2M2(μ-C8H8)非常接近;而Cp2Fe2(μ-B4N4H8)基态结构与Fe为4配位的Cp2Fe2(μ-C8H8)有所不同.Cp2M2(μ-B4N4H8)(M=V,Cr,Mn,Fe)基态结构分别为含V-V三重键的三态、含Cr-Cr三重键的单态、含Mn-Mn双键的三态及含Fe-Fe单键的单态.     

m-4-m型Gemini表面活性剂对铂电极上亚甲蓝吸附溶出伏安行为的影响

在0.050 mol·L-1磷酸盐缓冲溶液(PBS)中(pH=6.4), 亚甲蓝(MB)在铂电极上于-0.2 V产生一对不明显的伏安峰. 当向溶液中加入阳离子型Gemini表面活性剂Br-C16H33N+(CH3)2-C4H8-N+(CH3)2C16H33Br-, Br-C12H25N+(CH3)2-C4H8-N+(CH3)2C12H25Br-或Br-C8H17N+(CH3)2-C4H8-N+(CH3)2C8H17Br-后, 亚甲蓝的氧化峰显著增高, 还原峰降低, 氧化还原峰峰电位均正移, 这和表面活性剂与MB在电极表面的协同吸附有关. 联接基团相同的Gemini表面活性剂, 其影响程度随烷基链的增长而逐渐增强. 增大表面活性剂的浓度, MB的氧化峰先升高后缓慢降低. 如当Br-C16H33N+(CH3)2-C4H8-N+(CH3)2C16H33Br-的浓度为15 μmol·L-1 时, 5 μmol·L-1 MB的氧化峰峰电流达到最大值. 此外,溶液pH值和富集电位等对MB及表面活性剂的吸附亦有影响.     

内包金属富勒烯衍生物La@C82-(C4N2H8)mHn的合成与表征

在常温、Ar气保护下研究了金属富勒烯与哌嗪(Piperazine)的反应, 并用硅胶柱分离了3种金属富勒烯衍生物. 用激光解析飞行时间质谱、紫外-可见-近红外光谱和傅里叶变换红外光谱等手段分析确定其结构分别为La@C82-C4N2H8, La@C82-C4N2H8-H8和La@C82-(C4N2H8)2-H6. 对比C60与哌嗪的反应结果发现, 与空富勒烯相比, 金属富勒烯反应活性更高, 产物加成数目更多.     

两性孪联表面活性剂的合成及溶液性质

用C10～C16脂肪醇与2-氯-2-氧-1,3,2-二氧磷杂环戊烷低温反应生成环状磷酸酯的中间产物,再用N,N-二甲基十二胺在亲核溶剂中65℃下开环反应合成了4种含N 和磷酸根阴离子的两性孪联表面活性剂C10-C12、C12-C12、C14-C12和C16-C12,其质量收率分别为32%、54%、18%和28%。产物的结构通过1HNMR和元素组成分析,表明两性离子表面活性剂C、H、O、N的分析值与理论计算值偏差不超过0.3%。四种表面活性剂的临界胶束浓度(cmc)在0.0072~0.0125mmol/L之间,临界胶束浓度时表面张力(γcmc)依次为23.90、25.61、27.68和36.08mN/m。其中,C10-C12、C12-C12和C14-C12有较好的界面活性,加入盐可以使表面活性剂与烷烃间的界面张力下降,但下降程度有限,不能达到超低界面张力(10-3mN/m)。     

Surfactant-free hydrothermal synthesis of highly tetragonal barium titanate nanowires: a structural investigation

Barium titanate nanowires synthesized with a surfactant-free hydrothermal method have been characterized by various techniques such as transmission electron microscopy (TEM), scanning electron microscopy (SEM), synchrotron X-ray diffraction, X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The TEM and SEM analyses show the uniform cylindrical nanowires. The Rietveld refinement with synchrotron X-ray powder diffraction showed that the lattice parameters of cubic and tetragonal phases were a (= b = c) = 4.0134 A and a (= b) = 3.9998 A, c = 4.0303 A, respectively. The final weighted R-factor, R(wp), was 6.75% and the goodness of fit indicator was 1.30. The mass fraction of tetragonal and cubic phases based on the refined scale factor for the two phases were 98.4% and 1.6%, respectively, which clearly show the nanowires are tetragonal. The XPS analysis has shown that as-obtained BaTiO3 nanowires were phase pure. The Raman spectra confirm the tetragonal phase of the BaTiO3 nanowires. The dielectric constant measurement shows the shift in the transition temperature (Tc = 105 degrees C) compared to the bulk transition temperature (Tc = 132 degrees C). The dielectric constant at Tc was 174 measured at 1 kHz frequency.     

氮气氛中合成杂氮球烯,碳纳米管及纳米晶体的研究

氮气氛中合成杂氮球烯、碳纳米管及纳米晶体的研究詹梦熊，余荣清，王育煌，杨士姚，程大典，刘朝阳，郑兰荪（厦门大学化学系，厦门，３６１００５）关键词杂氮球烯，碳纳米管，纳米晶体，氮气氛自球烯及碳纳米管常规制备方法问世以来［１，２］，制备方法的改进一直成为...     

六方硼碳氮化合物的溶剂热合成与表征

采用溶剂热合成方法,以无水乙腈、叠氮化钠和四氟硼酸钠为原料,以苯为溶剂,在温度为400℃条件下,成功合成出了硼碳氮(BCN)三元化合物.利用X射线粉末衍射(XRD)、Fourier变换红外光谱(FTIR)、透射电子显微镜(TEM)、选区电子衍射(SAED)、X射线能谱(EDS)和电子能量损失谱(EELS)对合成产物进行了表征.XRD和SAED分析表明,合成产物为六方相,晶格常数为a=0.2678nm,c=0.6639nm;TEM结果表明,合成产物中存在纳米棒和四方柱状块体BCN;EELS和EDS分析表明,产物由B,C,N三种元素组成,化学式为B0.23C0.60N0.17;FTIR分析表明样品中存在C—N,B—C和B—N键,表明B,C,N三元素之间达到了原子级化合.     

Pt2Mo3N and PdPtMo3N: new interstitial nitrides prepared from freeze-dried precursors

The molybdenum bimetallic and trimetallic nitrides Pt₂Mo₃N and PdPtMo₃N have been synthesized by ammonolysis of the stoichiometric amorphous precursor, obtained by freeze drying of aqueous solutions of the appropriate metal salts. These compounds have been characterized by elemental analysis, energy-dispersive analysis of X-rays, X-ray diffraction, scanning electron microscopy, transmission electron microscopy and thermogravimetry analysis under an oxygen atmosphere. Pt₂Mo₃N and PdPtMo₃N crystallize in the cubic space group P4₁32 (213), with lattice parameters of a=6.83586(4) and 6.82542(3) Å, respectively, and form with the unusual filled β-manganese structure. These compounds are stable under air up to 580 K, the oxidation being complete at 910 K.     

双离子液体基多孔炭的制备与电化学性能

以质子型离子液体1-氢-3-乙烯基咪唑硫酸氢盐(HVImHSO₄)为主炭源, 以1-丁基-3-甲基咪唑六氟磷酸盐(BMImPF₆)为助剂, 在氮气气氛、 1000 ℃下一步炭化得到氮、 磷、 硫共掺杂多孔炭. 通过N₂吸附-脱附、 扫描电子显微镜(SEM)、 透射电子显微镜(TEM)、 X射线衍射(XRD)、 拉曼光谱(Raman)、 热重分析(TGA)和X射线光电子能谱(XPS)等技术对多孔炭进行了分析表征. 结果表明, 多孔炭的孔结构以微孔为主, 最高比表面积可达1111 m²/g, 其微晶结构中无定形碳和石墨化碳并存; 多孔炭中的氮主要以季氮(N-Q)、 吡咯氮(N-5)和吡啶氮(N-6)的形式存在, 磷以磷-氧(N—O—P)键合形式为主, 硫主要以噻吩硫(C—S—C)为主. 在6 mol/L KOH溶液、 三电极体系中, 多孔炭在0.5 A/g电流密度下的比电容为138 F/g; 在10 A/g电流密度下的比电容为100 F/g; 在2 A/g电流密度下循环充放电10000次, 其比电容保持率为95.8%, 显示出良好的电化学性能.     

Surface active properties of N-(2-Aminoethyl)-3-aminopropyltetrasiloxane lactobionamide and aggregation behavior in aqueous solution

The aggregation behavior of tetrasiloxane-lactobionamide (Si4N2-LA) in aqueous solution has been characterized by dynamic light scattering (DLS), negative-stained transmission electron microscopy (TEM) and X-ray Diffraction methods. Compared with the micellar sizes 7.0 nm of n-dodecyllactobionamide (C12Glu2), the Si4N2-LA molecule can self-assemble into spherical vesicle with diameters in the range from 60 to 300 nm.     

立方规则孔道结构含锆介孔氧化硅的合成与表征

以三嵌段共聚物为模板剂, 利用溶剂挥发法合成了具有立方相的含锆介孔氧化硅材料, 并对其结构进行了表征, 初步研究了其生成机理.     

Phase evolution, texture behavior, and surface chemistry of hydrothermally derived scandium (hydrous) oxide nanostructures

Nanostructured scandium hydrous oxides were hydrothermally synthesized at 180 degrees C for 18 h, using NaOH, NH(4)OH, and KOH as the bases. They were characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption, thermogravimetry and differential thermal analysis (TG-DTA), infrared and Raman spectroscopy, and pyridine adsorption. XRD and TEM measurements showed that the nature and concentration of the bases played key roles in determining the phasic composition, texture behavior (shape and size), and surface chemistry of the hydrothermal products. In addition, the shape evolution of the crystalline products seemed to be closely connected with their crystal structures. As the basicity value was raised from pH 10 to 5 mol L(-1) NaOH (or KOH), alpha-ScOOH nanorods, alpha-ScOOH nanosized hexagonal-like plates, and cubic Sc(OH)3 cubes/cuboids in micrometer size were produced in turn; while within pH 10-12 using NH4OH, gamma-ScOOH nanosized lozenge-like plates were mainly obtained. According to XRD, TEM, and TG-DTA results, all the as-prepared nanostructured ScOOH and micrometric Sc(OH)3 could be converted to cubic Sc2O3 with sustained crystalline shape via calcination at 500 degrees C. Pyridine adsorption revealed the existence of Lewis acid sites on the surfaces of the nanostructured alpha-ScOOH samples and some of their Sc2O3 counterparts calcined at 700 degrees C. The alpha-ScOOH nanorod sample displayed the strongest Lewis acidity among all the samples tested, due to its highest surface area as determined by N2 adsorption. Finally, an olation-oxolation process based on a dissolution/recrystallization mechanism accounts for the formation of various ScOOH polymorphs and Sc(OH)3 with different shapes.     

Study of Surface Reaction of Spinel Li(4)Ti(5)O(12) during the First Lithium Insertion and Extraction Processes Using Atomic Force Microscopy and Analytical Transmission Electron Microscopy

Spinel lithium titanate (Li(4)Ti(5)O(12), LTO) is a promising anode material for a lithium ion battery because of its excellent properties such as high rate charge-discharge capability and life cycle stability, which were understood from the viewpoint of bulk properties such as small lattice volume changes by lithium insertion. However, the detailed surface reaction of lithium insertion and extraction has not yet been studied despite its importance to understand the mechanism of an electrochemical reaction. In this paper, we apply both atomic force microscopy (AFM) and transmission electron microscopy (TEM) to investigate the changes in the atomic and electronic structures of the Li(4)Ti(5)O(12) surface during the charge-discharged (lithium insertion and extraction) processes. The AFM observation revealed that irreversible structural changes of an atomically flat Li(4)Ti(5)O(12) surface occurs at the early stage of the first lithium insertion process, which induces the reduction of charge transfer resistance at the electrolyte/Li(4)Ti(5)O(12) interface. The TEM observation clarified that cubic rock-salt crystal layers with a half lattice size of the original spinel structure are epitaxially formed after the first charge-discharge cycle. Electron energy loss spectroscopy (EELS) observation revealed that the formed surface layer should be α-Li(2)TiO(3). Although the transformation of Li(4)Ti(5)O(12) to Li(7)Ti(5)O(12) is well-known as the lithium insertion reaction of the bulk phase, the generation of surface product layers should be inevitable in real charge-discharge processes and may play an effective role in the stable electrode performance as a solid-electrolyte interphase (SEI).     

Surfactant-free thermal decomposition route to phase pure tricobalt tetraoxide nanoparticles from cobalt(II)-tartrate complex

Tricobalt tetraoxide nanoparticles have been successfully synthesized following a ‘bottom-up’ approach by surfactant-free thermal decomposition of cobalt(II)-tartrate complex obtained by a modified sol–gel route. The synthesized complex was characterized by Fourier transform infrared (FT-IR) spectroscopy, elemental and thermogravimetric-differential thermal analysis (TG–DTA). The nanoparticles were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and Raman studies. The powder XRD pattern furnished evidence for a face-centered cubic structure of Co₃O₄. With the rise in calcination temperature from 400 through 500 to 600 °C, the average crystallite sizes of Co₃O₄ were found to increase from 28 through 36 to 46 nm. The TEM image revealed a faceted morphology of the as-synthesized Co₃O₄ nanoparticles. The high-resolution TEM image indicated the interplanar separation to be 0.28 nm which corresponds to the (220) plane in face-centered cubic Co₃O₄. The electron diffraction (ED) pattern showed single-crystalline nature of the synthesized nanoparticles. Raman spectrum showed four characteristic peaks of Co₃O₄ which further confirmed the phasic purity of the material.