烟碱类异黄酮的合成及其性能研究

用红外、核磁、质谱、元素分析仪表征所合成的两个烟碱类异黄酮;研究溶剂及浓度对其荧光光谱的影响,以及其抑茵性能.结果表明,其环己烷溶液荧光强度最大,浓度也有显著影响;且其对大肠杆菌、尤其是对金黄色葡萄球菌有较好的抑制作用.     

α(β)-四-(4-甲氧基苯氧基)酞菁的合成、表征和光谱性质

以3-(4-甲氧基苯氧基)邻苯二腈和4-(4-甲氧基苯氧基)邻苯二腈为起始原料分别合成了α-四(4-甲氧基苯氧基)酞菁和β-四(4-甲氧基苯氧基)酞菁,通过红外光谱和紫外可见光谱表征了其结构,并讨论了取代基引入的位置对酞菁紫外可见光谱和荧光光谱的影响。     

含咔唑基2,2′:6′,2″-三吡啶衍生物的合成及其光学性质研究

设计合成了含咔唑基团的2,2′∶6′,2″-三吡啶衍生物W1~W3,运用核磁共振氢谱,核磁共振碳谱对目标化合物进行了表征;研究了W1~W3分子的单光子荧光和双光子荧光光谱,并在密度泛函理论水平上,利用少态模型对W1~W3分子进行初步理论研究,理论计算结果与实验结果得到较好的吻合,为寻找新型双光子材料进行了有益的探索。     

含咔唑基2,2':6',2"-三吡啶衍生物的合成及其光学性质研究

设计合成了含咔唑基团的2,2':6',2"-三吡啶衍生物W1～W3,运用核磁共振氢谱,核磁共振碳谱对目标化合物进行了表征;研究了W1～w3分子的单光子荧光和双光子荧光光谱,并在密度泛函理论水平上,利用少态模型对W1～w3分子进行初步理论研究,理论计算结果与实验结果得到较好的吻合,为寻找新型双光子材料进行了有益的探索.     

树枝状8-羟基喹啉锌的合成和荧光性能研究

通过收敛法合成了2种不同树枝状8-羟基喹啉配体，产物通过核磁共振（NMR）和红外（IR）进行表征；并通过荧光光谱对树枝状8-羟基喹啉配体及Zn（Ⅱ）金属配合物的性能进行研究，结果表明这些配体和Zn（Ⅱ）配合物均能溶于常见的溶剂，树枝状修饰使荧光强度变大，树枝状结构的外围官能团影响荧光性质；树枝状8-羟基喹啉锌的荧光出现明显的红移，有望在有机电致发光材料领域中得到广泛应用。     

2-烷硫基-4-羟基-1,3,3a,7-四氮茚的合成研究

本文介绍了２－烷硫基－４－羟基－１，３，３ａ，７－四氮茚化合物的合成方法；并用红外光谱、液质联用谱、紫外光谱等实验方法以及理论计算对其进行分析测试表征。     

4-羟基苯甲酸-2′-辛酯的合成

以对羟基苯甲酸为起始原料 ,经羟基保护、酯化和脱羟基保护三步反应 ,合成了难以用传统酯化法制备的 4 羟基苯甲酸 2′ 辛酯 ,总收率 6 5 % ,产物结构经IR及MS鉴定。     

α(β)-四-苯氧基金属酞菁的合成、表征和光谱性质

以3-硝基邻苯二腈和4-硝基邻苯二腈为原料分别合成了1,8,15,22-四-苯氧基酞菁铜(镍)和2,9,16,23-四-苯氧基酞菁铜(镍),通过IR和UV-Vis光谱进行了表征,并讨论了取代基的取代位置和中心离子对酞菁Q带最大吸收波长的影响。     

4-羟基苯甲酸-2'-辛酯的合成

以对羟基苯甲酸为起始原料,经羟基保护、酯化和脱羟基保护三步反应,合成了难以用传统酯化法制备的4-羟基苯甲酸-2'-辛酯,总收率65%,产物结构经IR及MS鉴定.     

Li2B4O7:Eu3+荧光体的合成及表征

利用Li₂B₄O₇作为基质,掺杂稀土元素Eu³⁺,在空气中合成了Li₂B₄O₇:Eu³⁺荧 光体.探讨了体系的烧结条件,分析了晶体结构,并研究了该体系的荧光性质.结果表明,体 系中同时存在着[BO₄]和[BO₃]结构;稀土离子Eu3+的发光以电偶极跃迁⁵D₀-⁷F₂为主,处 于非中心对称的格位上,并且可以很好地存在于基质中.     

Synthesis and conductivity studies of piperidine-4-carboxylic acid functionalized Fe3O4 nanoparticles

Piperidine-4-carboxylic acid (PPCA) functionalized Fe₃O₄ nanoparticles as a novel organic–inorganic hybrid was fabricated and characterized by XRD, FT-IR, VSM, and TEM techniques. Its detailed electrical properties are also presented. Composition was determined as Fe₃O₄, while particles were observed to have spherical morphology. VSM measurement proved the super-paramagnetic property of the as synthesized nanocomposite. ac and dc conductivity measurements indicated semiconductor characteristics and changing trends with temperature because of reorganization of the nanocomposite. dc conductivity is strongly temperature dependent and is classified into three regions. Analysis of the real and imaginary parts of the permittivity of nanocomposite showed the ionic polarization mechanism consisting of ionic conductivity and interfacial polarization.     

Synthesis,crystal structure,optical and third order nonlinear optical properties of phosphoric acid pyridine-1-ium-2-carboxylate

A semi-organic nonlinear optical material phosphoric acid pyridine-1-ium-2-carboxylate (PAPC) crystal has been synthesized and grown. Vibrational spectral analysis and NMR spectral analysis has been carried out. Mechanical studies on the grown crystal has been performed which disclose the material belongs to soft materials category. The thermal behaviour of the grown crystal has been investigated by thermogravimetric and differential thermal analysis. UV–Visible spectral analysis has been carried out which reveals that the grown crystal is transparent in the entire visible region with the lower cut-off wavelength of 298 nm and the derived optical constant attests the suitability of this material for non-linear optical applications. The third order nonlinearity has been studied by z-scan method and the enhanced third-order nonlinearity shows PAPC is a potential material for device applications. Second harmonic generation efficiency has been studied by Kurtz and Perry powder test and is found as 0.14 times greater than the KDP.     

Synthesis and optical properties of SnO(2) nanorods

Well-crystalline SnO(2) nanorods have been synthesized successfully via a lithium-assisted solution-phase method. The structural and optical properties of the SnO(2) nanorods were investigated using x-ray powder diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, and infrared, Raman and photoluminescence spectroscopy. The experimental results show that lithium addition plays a critical role in the formation of SnO(2) nanorods, and the correlation between the surface energy change and morphological evolution of this material is also discussed. This approach provides an economically viable route for large-scale synthesis of this nanostructured material.     

Growth,optical and microstructural properties of PbB4O7 plate crystals

Centimeter-sized optical quality plate-like PbB₄O₇ crystals have been grown by Czochralski method. The fundamental absorption edge has been found at 237 nm (corresponding bandgap 5.75 eV) with the distinct sideband protruding up to 300 nm. The crystals are well faceted with the (1 0 0), (0 1 0) and (1 0 1) planes, (1 0 0) surfaces being mostly developed. The etching in diluted nitric acid (5 wt.%) at the temperature of 90 °C have been used to reveal the defect structure and remove melt residuals. The (1 0 0) surface shows the presence of etching pits and twin boundaries. The Kikuchi line pattern and developed microrelief with the roughness of ∼8 nm have been observed by RHEED and AFM, respectively.     

甘氨酸燃烧法合成Sr2CeO4及其发光性质研究

为制备具有优良性能的蓝色荧光粉,首次采用甘氨酸-硝酸盐燃烧法合成了Sr2CeO4,利用热重-差热分析仪、X射线粉末衍射仪、扫描电镜等技术对其形成过程、物相结构、形貌粒度、发光性质进行了研究.结果表明:燃烧后的前驱物经800℃焙烧已有目标产物Sr2CeO4生成,1100℃时可得到较纯正交晶系的Sr2CeO4相.颗粒的形貌为不规则球形,平均粒径在80 nm左右.发光性质研究表明:Sr2CeO4荧光粉的激发光谱是宽带双峰结构,此宽带属于Ce4+的电荷迁移带,两个峰分别位于305 nm和348 nm,后者为主峰.用348 nm紫外光激发样品,发出明亮的蓝光,其发射光谱也是一个宽带,最大峰位于470 nm,此峰属于Ce4+的f→t1g跃迁.发光强度在800~1100℃随温度升高而增强.     

Nonlinear optical, piezoelectric, and acoustic properties of SrB4O7

We have measured the second-order nonlinear optical susceptibilities of an SrB₄O₇ crystal and have determined its electromechanical coupling coefficients, piezoelectric charge and voltage constants, and bulk acoustic wave velocities by a resonance method using high-Q resonators. In addition, the dielectric permittivity of the crystal has been measured at 1 kHz.     

Growth and optical properties of ZnIn2Se4 films

Thin films of ZnIn₂Se₄ were deposited on quartz substrates at 297 K by the conventional thermal evaporation technique. The as-deposited films were amorphous. On annealing at 623 K under vacuum for 3 h, the films crystallized with a preferred (1 1 2) orientation corresponding to the chalcopyrite-type structure. Films deposited on a quartz substrate heated to 573 K were also crystalline. The optical constants were computed from the measured transmittance and reflectance at normal incidence of light in the wavelength range 400 to 2000 nm. The analysis of the data gave a direct gap of 2.2 and 2.06 eV for the amorphous and crystallized films, respectively. The dispersion curve exhibited a peak above the absorption edge. An indirect gap of 1.8 eV for the crystallized films and a direct forbidden gap of 1.75 eV for the amorphous films were also deduced. A direct allowed transition with a gap of 2.065 eV and an indirect transition with a gap of 1.69 eV were deduced for the crystalline films deposited on the heated substrate.     

钼掺杂的铌镧酸的合成及光催化性能研究

通过高温固相反应合成了钼掺杂的铌镧酸钾系列,并通过离子交换反应制备出钼掺杂的铌镧酸系列;采用X-射线衍射、紫外可见漫反射光谱、原子吸收光谱、比表面积测定等对所制得的样品进行了表征.在甲醇为给电子体,铂为助催化剂的条件下,用波长＞290nm的100W汞灯辐照时,钼掺杂的铌镧酸系列表现出了分解水产生氢气的光催化活性,当掺杂浓度为Mo/Nb=2.5mol%时,其产氢速率达到最大值.     

Linear and nonlinear optical properties of 4-nitrobenzoic acid (4-NBA) single crystals

4-Nitrobenzoic acid (4-NBA) single crystals were studied for their linear and nonlinear optical properties. The crystals were grown by slow solvent evaporation method at room temperature. The structure and functional groups were confirmed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopic studies. The 4-NBA crystal has an optical absorption at 263 nm and a wide transparency window for the visible light. Theoretical predictions for the measured optical absorption and charge transfer mechanism in 4-NBA were explained with HOMO and LUMO illustrations. The crystal is found to be birefringent and has produced an optical quality interference pattern. The optic plane of the crystal is observed along \(\langle 1 0 0\rangle \) direction. The crystal exhibits nonlinear optical effects viz. reverse saturable absorption and self-defocussing of laser beam. Considerable nonlinear refraction \((n_{2})\) and nonlinear absorption (\(\beta \)) coefficients and third-order nonlinear optical susceptibility \((\chi ^{(3)})\) were determined using Z-scan technique.     

Synthesis and optical properties of TiO2 nanoparticles

Ultrafine TiO₂ particles have been synthesized successfully by a facile gas flame combustion method. The synthesized sample is characterized by X-ray diffraction (XRD), transmission electron micrograph (TEM), Fourier transform infrared (FTIR), and photoluminescence (PL) spectroscopy. The as-prepared TiO₂ nanoparticles appear to be a single anatase crystalline phase and the diameter is about 9 nm. Besides a sharp emission at 398 nm originating from the radiative annihilation of excitions, a weak broad band at about 434 nm from the defect-related emission is also discussed.