电照相用苝四羧酸二酰亚胺系有机光导材料

苝四梭酸二酞亚胺系(PTCDI)化合物具有较强的荧光性能和光稳定性.是一类非常适合作为光电转化材料的有机化合物.目前,该化合物的应用已涉及到太阳能转化材料、电子照像用材料、液晶材料等领域^[1,2],象酞菁、方酸类化合物一样^[3,4],目前国际上已有以苝类化合物制备的有机光导鼓(OPC),但对这类化合物的研究,仅局限在少数几个化合物上,搞清结构与性能之间的关系,对苝类化合物作为光导材料的应用,就显得尤为重要.     

四(4-重氮基苯基)卟啉的合成及其与聚苯乙烯磺酸钠自组装的研究

卟啉是一类重要的功能性小分子染料,近年来,在光化学治疗^[1,2]、光电转换^[3,4]、传感元件^[5]、烯烃环氧化催化剂^[6]和光敏化剂^[7]等方面的研究与应用引起了人们的广泛注意.通过两亲卟啉分子衍生物,或带有负电荷的卟啉衍生物,特别是带磺酸基的卟啉分子与正离子聚电解质自组装,制备带有卟啉结构单元的LB膜和自组装膜已有很多报道^[8～14].     

三氯锗取代丙酰氢化噻唑-2-硫酮类化合物及其水解产物的合成

某些有机锗化物,例如β-羧乙基锗倍半氧化物及其衍生物能诱发干扰素,对癌症有一定疗效,日本专利报道丙酰胺基锗倍半氧化物及其衍生物也具有抗癌活性^[2,3],白明章等曾合成丙酰芳胺基锗倍半氧化物^[4]。     

时间分辨(荧光)各向异性及其在高分子科学研究中的应用

荧光偏振(fluorescence polarization)的实验研究始于1929年Perrin^[1]对荧光小分子在溶液中寿命的测定。直到二十年后,这一技术才被Weber等^[2]用于对蛋白质分子运动的研究。     

4-(4-羧基苯氧基)间苯二甲酸构筑的过渡金属配位聚合物: 合成、 晶体结构、 荧光传感与光催化

采用水热法合成了4个配位聚合物[Zn(Hcpoia)(2,2'-bpy)·H₂O]_n(1)和[M(Hcpoia)(phen)]_n·nH₂O[M=Zn(2), Mn(3), Co(4); H₃cpoia=4-(4-羧基苯氧基)间苯二甲酸; 2,2'-bpy=2,2'-联吡啶; phen=1,10-邻菲罗啉], 利用X射线单晶衍射分析确定了配合物的晶体结构. 配合物1为一维链状结构, 中心Zn ²⁺离子的配位环境为[ZnO₄N₂]扭曲的八面体构型, 配体Hcpoia ^2-以μ₁∶η ¹η ⁰和μ₁∶η ¹η ¹配位模式桥连相邻的Zn ²⁺离子. 配合物2和4的结构与配合物1类似, 是由配体Hcpoia ^2-以μ₁∶η ¹η ⁰和μ₁∶η ¹η ¹配位模式联接[MO₄N₂]结构单元而形成的一维链状结构. 配合物1, 2和4中均存在分子间氢键(O—H…O), 氢键的存在使一维链连接形成二维超分子结构. 配合物3为二维网状结构, Mn ²⁺离子的配位环境为[MnO₄N₂]扭曲的八面体构型, 配体Hcpoia ^2-以μ₂∶η ¹η ¹配位模式桥连相邻Mn ²⁺离子形成[Mn₂COO₂]结构单元, 该结构单元被Hcpoia ^2-连接形成二维结构. 在4个配合物中, 2,2'-bpy和phen配体均以端基的形式与金属离子螯合配位. 研究了水溶液中抗生素分子和Fe ³⁺离子对配合物1与荧光强度的影响, 实验结果表明, 甲硝唑、 Fe ³⁺离子对配合物1有荧光猝灭作用, 并进一步考察了甲硝唑浓度和Fe ³⁺离子浓度对配合物1荧光强度的影响. 基于荧光猝灭机理, 配合物1可以用作荧光传感器检测水溶液中的甲硝唑和Fe ³⁺离子. 研究了配合物4对罗丹明B(RhB)的催化降解性能, 发现在氙灯照射和H₂O₂存在条件下, 配合物4对RhB具有较好的光催化降解作用.     

植物生物分子的电分析化学研究Ⅷ.秋水仙碱的微分脉冲极谱行为及分析应用

秋水仙碱是近年来新发现的有前途的抗癌植物有效成分。秋水仙碱的测定方法,如容量滴定法^[1]、电位滴定法^[2]、紫外分光光度法^[3]、荧光分析法^[4]和高效液相色谱法^[5]等,手续均不太简便。电化学分析研究秋水仙碱主要有阳极伏安法^[6]和交流极谱法^[7],前者因使用固态电极,重现性较差。后者用非水溶剂作介质,灵敏度不高。     

焦磷酸络锰三价离子引发淀粉-丙烯酰胺的接枝共聚合

将带有极性基团的乙烯类单体通过化学接枝到淀粉或纤维素之类的天然多糖上,可作为絮凝剂、脱除剂和粘接剂^[1～3],近来已发展为高吸水性材料和石油分离剂^[4]。用Ce⁴⁺引发乙烯类单体接枝到淀粉和纤维素类已有报道^[5]。Rayonier用Mn³⁺的焦磷酸盐络合物引发接枝乙烯类单体至纤维素及其衍生物上^[6];Cenita等用Mn³⁺引发MMA、AN接枝淀粉^[7]。本文以焦磷酸络锰离子(Mn³⁺)作引发剂、丙烯酰胺(AM)为单体、淀粉为接枝基体进行接枝共聚,这一工作目前在国内外尚未见报道。     

β,γ-不饱和仲烃基乙酰乙酸乙酯的皂化及芳樟醇衍生物的合成

本文作者^[1]曾从乙烯基类溴化镁与亚烃基乙酰乙酸乙酯的共轭加成反应得到了一系列的β,γ-不饱和仲烃基乙酰乙酸乙酯。作者之一^[2]曾报道过取代烃基对于丙二酸酯皂化速度的影响,因此研究取代烃基对于乙酰乙酸乙酯皂化反应的影响是有意义的。关于芳樟醇及其衍生物的各种合成方法,文献上曾有记载^[3~6]。     

两种卟啉化合物在Ag溶胶表面的紫外-可见吸收光谱和表面增强拉曼散射光谱研究

表面增强拉曼散射(SERS)自1974年被Fleischmann等^[1]发现以来,日益受到人们的重视.通过SERS谱图分析,可以获得物质结构及其与基体作用的信息.由于SERS可使拉曼信号增强10⁵~10⁶倍^[2],并且在某些情况下银胶还能使表面吸附质的荧光猝灭^[3,4], SERS常用来检测一些普通拉曼光谱难以检测的样品和考察界面络合物的形成.     

星型二苯乙烯衍生物的三光子吸收及多光子荧光发射

用飞秒Ti:sapphire激光测定了星型二苯乙烯衍生物2,5-二{4-{2-N,N-二[4-(2-N,N-二苯基氨基苯乙烯基)苯基]氨基苯乙烯基}苯基}-1,3,4-噁二唑(DPASPO)和1,2,4,5-四(4-N,N-二苯氨基苯乙烯基)苯(PASB)的三光子吸收谱和多光子上转换荧光光谱. 研究了星形八极矩分子DPASPO和PASB的线性吸收、单光子荧光及荧光寿命. 在800 nm波长的飞秒激光激发下, DPASPO和PASB在二氯甲烷溶液中发出很强的黄绿色双光子上转换荧光, 荧光峰分别位于583 nm和547 nm. 在1260 nm波长的飞秒激光激发下, DPASPO和PASB的三光子上转换荧光峰分别位于612 nm和572 nm. 采用非线性透过率法测得DPASPO和PASB最大三光子吸收截面分别为16.69×10^－79 cm⁶•s²和6.81×10^－79 cm⁶•s². 这些二苯乙烯衍生物的三光子吸收截面较大. 在这些星型分子中, 三光子吸收增强来源于二苯乙烯分支的增加, 共轭体系的扩展以及分子内跨越空间电荷离域.     

高效液相色谱法测定麻黄及其制剂中的麻黄类生物碱和川芎嗪

 用RP HPLC分离测定了麻黄及其制剂中的麻黄类生物碱及川芎嗪。采用色谱柱Nova Pak C18(15 0mm×3.9mmi.d .) ,二极管阵列检测器 (DAD)。测定麻黄类生物碱时 ,以甲醇 0 .0 2mol/LKH2 PO4 乙酸 三乙胺 (体积比为 4∶96∶0 .2∶0 .0 1)为流动相 ,在 2 10nm波长下检测 ;测定川芎嗪时 ,以甲醇 水 乙酸 (体积比为 35∶6 5∶0 .5 )为流动相 ,在 2 90nm波长下检测。分别测定了麻黄原药材、中成药 (小儿清肺丸、鹭鸶咳丸 )中麻黄碱、伪麻黄碱、去甲基麻黄碱、去甲基伪麻黄碱和川芎嗪的含量。     

催化荧光法测定痕量铜的探究性实验设计与实践

基于铜(Ⅱ)对高碘酸钾氧化番红花红T具有催化作用,建立催化动力学荧光法测定痕量铜的新体系。体系在加入铜(Ⅱ)后,在580 nm波长处的荧光强度明显降低,且在2.50-32.50 ng?m L~(-1)范围内铜(Ⅱ)的浓度与体系的lg(F_0/F)呈线性关系。基于催化动力学荧光分析法测定痕量铜的新方法实验,探讨了仪器分析实验课探究性实验的设计与实施方法。同时,为实现探究性实验教学,教师要严把命题关和可行性分析关,以期达到探究性实验设计的教学效果。     

基于氮掺杂碳点的荧光增强简便、快速而准确地检测环丙沙星

以苹果酸为碳源,磷酸铵提供氮源,采用固态热解法一步合成一种水溶性的、氮掺杂的蓝色荧光碳点(N-CDs)。 所得到的碳点荧光量子产率高达20.7%,形貌近似球形,平均粒径约为3.3 nm。 基于环丙沙星(CIP)对碳点的荧光增强作用,建立了一种CIP的定量检测方法。 最佳实验参数为:碳点浓度为7.5 μg/mL,pH值为5.9,孵化时间为5 min。 在此实验条件下,碳点的荧光强度增加值(ΔF)和CIP的浓度在0.39~40.00 μmol/L范围内呈良好的线性关系,方法的检出限为0.12 μmol/L,相对标准偏差(n=5)为4.2%。 干扰实验结果指出,除了铜离子具有明显的影响外,其它共存物质的干扰可以忽略不计,而铜离子的干扰可通过加入草酸铵来掩蔽。 最后利用所构建的荧光传感器对实际样品中CIP进行检测,回收率在93%~107%之间。 本研究为CIP定量分析提供了一种简单、快速、灵敏度高、选择性好而有效的测定方法。     

Picosecond emission anisotropy decays of dimethyl aminobenzonitrile

Picosecond polarized fluorescence experiments on DMABN (4-(dimethyl amino) benzonitrile) in polar solvents and toluene are reported. From the detected polarized fluorescence components emission anisotropy histograms are constructed and compared with the synthetic data simulated for the energy levels scheme in DMABN. For the short-wavelength emission of DMABN vibronic coupling between the close-lying S₁ and S₂ energy levels occurs and leads to a vibronically mixed polarization of the S₁ (F_B) fluorescence. Low initial values of the emission anisotropy decays for the long-wavelength (F_A) emission are observed. This observation can be explained by an assumption that the internal twisting of the amino group in DMABN changes the angular orientation of DMABN and by an assumption that the emission dipole moment in the F_A emission band is not parallel to the absorption dipole moment in the S₂ (¹L_a) absorption band.     

Morphology evolution and location of ethylene–propylene copolymer in annealed polyethylene/polypropylene blends

Binary blends of linear low density polyethylene (PE) and polypropylene (PP), and ternary blends of PE, PP, and EP copolymer (EPR) were prepared in a finely mixed state. In all blends the ratio of PP to PE was 85/15. In some of the blends, the PE component was labeled with a fluorescent dye; in other blends, the EPR component was labeled. These blends were investigated by laser scanning confocal fluorescence microscopy [LCFM] as a function of annealing time as well as EPR compatibilizer content. In this way we were able to follow the evolution of sample morphology and the location of the EPR in the blends. The presence of EPR in the blends retards the growth of droplets of the dispersed PE phase. When EPR was added in amounts up to 5 wt %, it tended to cover the PE droplets in patches rather than form a true core-shell structure. In the LCFM images, the EPR/PP interface appeared sharper than the EPR/PE interface. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35 : 979–991, 1997     

Surface‐directed morphology evolution in ternary blends of polyethylene,polypropylene, and ethylene–propylene copolymer: A study by laser scanning confocal fluorescence microscopy

With laser scanning confocal fluorescence microscopy, we demonstrate a novel type of morphology evolution in moderately thick films (70–100 μm) of ternary blends of polypropylene (PP), polyethylene (PE), and ethylene–propylene rubber (EPR), in which EPR is labeled with a benzothioxanthene dye (HY‐EPR). The blends are prepared by solution blending, and the phase morphology evolves during the annealing of the blend films in a stainless steel mold. Our results indicate that wetting of the mold surface is a driving force in morphology evolution for the two blend compositions investigated. For 81/14/5 PP/PE/HY‐EPR, phase evolution within the mold results in a laminar structure and hydrodynamic channels, features which have previously been found in thin films of polymer blends as a result of surface‐directed spinodal decomposition. In a blend with a lower weight fraction of the dispersed phase (92/7/1 PP/PE/HY‐EPR), we find that the PE/HY‐EPR domains are larger and more polydisperse closer to the surface because of wetting of the mold wall. We also show that the phase morphology in these films can be controlled by the nature of one or both of the surfaces being varied. When one of the mold surfaces is replaced with a thin film of PP homopolymer, we observe draining of PE/HY‐EPR from the PP to the mold surface, which results in a bilayer structure. A trilayer morphology is likewise obtained by the replacement of both mold surfaces with PP. We also carry out three‐dimensional image reconstruction on a single PE/HY‐EPR particle within the 81/14/5 PP/PE/HY‐EPR blend to obtain detailed information on the interphase structure. We find that HY‐EPR of this composition (30/70 ethylene/propylene) fully coats the PE dispersed phase and partially penetrates the PE droplets. This result falls between the interphase structures found for previously investigated EPR compositions (40/60 and 80/20 ethylene/propylene). © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 637–654, 2003     

Determination of the antibacterial drug sulfamethoxazole in pharmaceutical preparations containing trimethoprim by spectrofluorimetry after derivatization with fluorescamine

An analytical method was developed for the determination of sulfamethoxazole (SMZ) in the presence of trimethoprim (TMP) by normal fluorescence. When both analytes are present a selective derivatization with fluorescamine of SMZ gives an intense fluorescent derivative with no interference from the other compound. The reaction was optimized to obtain the best analytical performance. The detection limit and the lower limit of quantitation of SMZ in the reaction medium was 5.2 ng/mL. The intra-day precision (relative standard deviation) was 1.51% for a 100 ng/mL SMZ standard solution and the inter-day precision over 7 days for a 100 ng/mL solution in the presence of 20 ng/mL TMP solution was 2.5%. The method has been applied to three pharmaceutical preparations containing both compounds, without any separation steps required.     

Microemulsion electrokinetic chromatography with laser-induced fluorescence detection for sensitive determination of ephedrine and pseudoephedrine

A selective and sensitive microemulsion electrokinetic chromatography with laser-induced fluorescence detection method was developed for the quantification of ephedrine (E) and pseudoephedrine (PE) derivatized with 4-chloro-7-nitrobenzo-2-oxa-1, 3-diazol. By a series of optimization, a running buffer composed of 20 mM borate + microemulsion (23.3 mM Sodium dodecyl sulfate/180.85 mM 1-butanol/16.4 mM n-heptane) +8% acetonitrile was applied for the separation of the derivatives. A linear relationship for E and PE was obtained in the range of 0.058-11.58 microg.mL(-1) (correlation coefficient: 0.9993 for E, 0.9995 for PE), and the detection limits for E and PE were 5.3 and 3.9 ng.mL(-1). The method was applied to the analysis of the two alkaloids in Chinese traditional herbal preparations with recoveries in the range of 96.9-105.4%.     

Determination of the antibacterial drug sulfamethoxazole in pharmaceutical preparations containing trimethoprim by spectrofluorimetry after derivatization with fluorescamine

An analytical method was developed for the determination of sulfamethoxazole (SMZ) in the presence of trimethoprim (TMP) by normal fluorescence. When both analytes are present a selective derivatization with fluorescamine of SMZ gives an intense fluorescent derivative with no interference from the other compound. The reaction was optimized to obtain the best analytical performance. The detection limit and the lower limit of quantitation of SMZ in the reaction medium was 5.2 ng/mL. The intra-day precision (relative standard deviation) was 1.51% for a 100 ng/mL SMZ standard solution and the inter-day precision over 7 days for a 100 ng/mL solution in the presence of 20 ng/mL TMP solution was 2.5%. The method has been applied to three pharmaceutical preparations containing both compounds, without any separation steps required. Received: 28 December 1998 / Revised: 28 April 1999 / Accepted: 30 April 1999     

壳聚糖在稀溶液中的聚集行为

壳聚糖在稀溶液中的聚集行为;荧光探针;荧光偏振;聚集行为