氧络铬卟啉配合物的合成结构及其氧化活性研究

本文选择不同配体（苯酚类和迭氮）通过Cr(III)(TPP)Cl (Al)的氧化还原取代，分别合成了四个新的铬（III）卟啉配合物，Cr(TPP)N_3P_Y(B_1), P-O_2NC_6H_4OCr(TPP)·THF (C1), P-CH_3OCoH_4OCr(TPP)·THF (D1), Cr(TPP)OC_6H_5·THF (E1)。通过元素分析，红外光谱、~1H NMR、ESR、MS和UV-Vis等分析、表征，确认了以上四种化合物。B1单晶进行了X－射线分析，得其晶体结构和分子结构，从而进一步证实了B1的组成。在CH_2Cl_2或C_6H_6中，氮气保护下，用PhIO直接氧化以上五种铬（III）卟啉配合物，合成并分离出了相应的高价氧络铬卟啉配合物，(PhI) O=Cr(▽)(TPP)Cl (A2), (PhI) O=Cr(▽)(TPP)N_3, (B2), P-O_2NC_6H_4O Cr(▽)(TPP) (1/2IPh) (C2), P-CH_3OC_6H_4O Cr(▽)(TPP) (1/2IPh) (D2), PhIO- Cr(IV)(TPP) (OC_6H_5)·P_Y (E2)。通过研究其元素组成，IR、UV－Vis、ESR、MS等分析，确定了以上五种化合物的组成。基中PhI和P_Y分子的位置尚无法确定。这两类高价氧络铬卟啉，是继右淑珍等第一次得到P450模型化合物的活性中间体－氧络铬（▽）四苯基卟啉对硝基苯甲酸配合物后，又一次得到的苯酸类和迭氮氧络铬卟啉配合物。不同的是，氧络铬（▽）卟啉配合物中都各有PhI分子，化合物E2是第一次得到的关键氧络铬（IV）卟啉配合物，类似于PhIO－Mn~(IV)(TPP)(P-H_2N C_6H_4 CO_2)。高价氧络铬卟啉配合物不稳定，室温下分解，暴露在空气中同时发生分解和还原。不过低温下比较稳定。在CH_2Cl_2或C_6H_6中，我们研究了上述五种氧络铬及Cr(TPP)ClPhIO对碳氢化合物和DNA碱基的氧化反应。不同摩尔比的PhIO-Cr(TPP)Cl对环已烷的氧化给出相同的产物，但转化率和产物分布不同。Al-PhIO和C_2-PhIO体内对碱基胞嘧啶，胸腺嘧啶，腺嘌呤的氧化反应呈阳性，氧化产物中都有尿素CO(NH_2)_2，其中胸腺嘧啶的氧化产物中含有CH_3CO-或CH_3CHOH。这说明氧络铬卟啉配合物能够氧化DNA碱基。氧络铬卟啉具有较高的氧化活性和立体选择性。比较不同轴向配体的氧络铬卟啉的氧化活性，其大小次序正好与其轴向配体的配位能力次序一致。这是由于轴向配体的给电子能力越强，通过中心离子铬向其周围转移的电荷就越多，导致氧络键的强度减弱，即其活性增加。上述研究结果表明，铬（III）卟啉配合物是P－450的较好的模型化合物，氧络铬卟啉配合物是其活性中间体。同时该研究结果支持了Groves等提出的定居卟啉配合物催化氧化机理。

旋涂薄膜的极化取向与松驰

本工作对三种极化非线性光学（NLO）高聚物进行了研究。1）有机染料掺杂型NLO高聚物：把分散红（DR1）和对硝基苯胺（p-NA）掺杂于无定型高聚物中，用旋涂法成膜，在掺杂高聚物Tg以上，用电晕极化法使薄膜中的染料分子取向。研究了电晕极化条件对取向效果的影响。具有高Tg的极化膜显示了好的取向稳定性；2）主链或侧链含生色基团的NLO高聚物：分散红以共价键接枝在高分子侧链或对硝基苯胺接枝在高分子主链。用UV-vis光谱法和偏振IR光谱法表征了NLO高聚物极化过程。同染料掺杂高聚物比较，主链型高聚物具有较好的取向稳定性。3）交聚型NLO高聚物：4-（2,3-二羟基丙氧基）-4'-硝基偶氮苯与六亚甲基二异氰酸酯的缩二脲进行电场极化交联反应。在较短时间内得到完全交联的NLO聚合物材料。采用变温FT-IR光谱及DSC对不同温度的交联过程进行了详细的研究。在适当的预聚温度和时间以及极化温度和电压等固化条件下，测得极化膜的d_(33)值。

Pressure dependence of the electronic subband structure of strained In0.2Ga0.8As/GaAs MQWs

We have measured low-temperature photoluminescence (PL) and optical absorption spectra of an In0.2Ga0.8As/GaAs multiple quantum well (MQW) structure at pressures up to 8 GPa. Below 4.9 GPa, PL shows only the emission of the n = 1 heavy-hole (HH) exciton. Three new X-related PL bands appear at higher pressures. They are assigned to spatially indirect (type-II) and direct (type-I) transitions from X(Z) states in GaAs and X(XY) valleys of InGaAs, respectively, to the HH subband of the wells. From the PL data we obtain a valence band offset of 80 meV for the strained In0.2Ga0.8As/GaAs MQW system. Absorption spectra show three features corresponding to direct exciton transitions in the quantum wells. In the pressure range of 4.5 to 5.5 GPa an additional pronounced feature is apparent in absorption, which is attributed to the pseudo-direct transition between a HH subband and the folded X(Z) states of the wells. This gives the first clear evidence for an enhanced strength of indirect optical transitions due to the breakdown of translational invariance at the heterointerfaces in MQWs.

纳米硅镶嵌氮化硅薄膜的制备及非线性光学性质研究

采用射频磁控反应溅射法结合热退火处理技术制备纳米硅镶嵌氮化硅（nc-Si/SiNx）复合薄膜。通过X射线能谱（EDS）、红外光谱（IR）、X射线衍射（XRD）及紫外-可见吸收光谱（UV-vis）的测定,对薄膜进行了组分、键合状态、结构及光学带隙的表征。采用皮秒激光运用单光束Z扫描技术开展了对该复合薄膜的非线性光学性质的研究,测得其三阶非线性折射率系数和非线性光吸收系数分别为10~(-8)esu和10~(-8)m/W量级,并将薄膜这种三阶光学非线性增强的原因归因于量子限域效应。

p型纳米硅与a-Si∶H不锈钢底衬nip太阳电池

报道了选用厚度为0．05mm的不锈钢箔作衬底，B掺杂P型氢化纳米硅作窗口层，制备成功开路电压和填充因子分别达到0．90V和0．70的nip非晶硅基薄膜单结太阳电池．UV-VIS透射谱和微区Raman谱证实所用p层具有典型氢化纳米硅的宽能隙和含有硅结晶颗粒的微结构特征．明确指出导致这种氢化纳米硅能隙展宽的物理机制是量子尺寸效应．

氢稀释对非晶硅碳(a-SiC:H)合金薄膜生长和光学特性的影响

用PECVD方法,以固定的甲烷硅烷气体流量比([CH4]/[SiH4]=1.2)和不同的氢稀释比(RH=[H2]/[CH4+SiH4]=12,22,33,102和135)制备了一系列的氢化非晶硅碳合金(a-SiC:H)薄膜.运用紫外-可见光透射谱(UV-VIS)、红外吸收谱(IR)、Raman谱以及光荧光发射谱(PL)测量研究了氢稀释和高温退火对薄膜生长和光学特性的影响.实验发现氢稀释使薄膜光学带隙展宽(从1.92到2.15 eV).高氢稀释条件下制备的薄膜经过1250℃退火后在室温下观察到可见光发光峰,峰位位于2.1 eV.结合Raman谱分析,认为发光峰源于纳米硅的量子限制效应,纳米硅被Si-C和Si-O限制.

Characterization of CdSe and CdSe/CdS core/shell nanoclusters synthesized in aqueous solution

CdSe nanoclusters overcoated with CdS shell were prepared with macapoacetic acid as stabilizer. The optical properties of CdSe nanoclusters and the influence of CdS shell on the electronic structures of CdSe cores were studied by optical absorption, photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopies. Based on PL and PLE results and the theoretical calculation on fine structure of bandedge exciton, a model of formation of excimer within the small clusters was proposed to explain the large Stokes shift of luminescence from absorption edge observed in PL results. (C) 2000 Elsevier Science B.V. All rights reserved.

5-氟尿嘧啶-β-环糊精结肠靶向前体药物的研究

5-氟尿嘧啶(5-Fluorouracil， 5-FU)是一种抗代谢药物，广泛用于临床治疗结直肠癌、胃癌、乳腺癌等多种癌症，但其首过代谢显著、亲脂性较低，选择性差、毒副作用大。为克服这些缺点人们对5-FU进行了大量的修饰工作，包括小分子修饰以及与各种载体形成微球、微囊、纳米粒、共价前药等。 环糊精(Cyclodextrin，简称CD)，可被结肠中的糖苷酶特异性地降解成小分子糖，而胃和小肠中由于缺乏相应的酶而使环糊精不被降解，这一特性在结肠药物的靶向输送及释放中有重要应用价值。环糊精中含有丰富的羟基，易进行化学修饰，将药物与环糊精通过共价键结合制成前药，使其在胃和小肠中不降解，而在盲结肠中被特异性的酶降解释出药物，达到结肠靶向释药的目的。研究表明，环糊精作为一种前药载体为结肠靶向释药和缓释、控释系统提供了一种有效的手段。 本工作选择5-氟尿嘧啶为模型药物、β-环糊精作为载体，通过中间体5-FU羧酸衍生物的制备及其与β-环糊精的偶联，合成了系列5-FU-β-CD前体药物，并利用紫外、红外、质谱、核磁、元素分析、热分析等手段对其进行结构表征。同时，还研究了前体药物的体外释药性质。具体内容包括： 1. 含有羧基的5-FU衍生物中间体的合成：(5-氟尿嘧啶-1-基)-乙酸(FUAC)、3-(5-氟尿嘧啶-1-基)-丙酸(FUPC)、5-(5-氟尿嘧啶-1-基)-戊酸(FUVC)的合成。 2. 中间体5-FU的羧酸衍生物与β-CD的偶联：分别通过以6-OTs-β-CD为中间体的取代法和活化酯法，合成了第一面取代和第二面取代的5-FU-β-CD大分子前体药物。在二面取代的前体药物制备中，通过改变原料的比例，合成了系列不同取代度(DS)的2-[(5-氟尿嘧啶-1-基)-乙酰基] -β-环糊精结合物。 3. 对上述前体药物进行体外释放研究：分别考察了前体药物在不同pH缓冲溶液中的水解行为及其在小鼠胃肠道人工体液中的酶解行为，并通过UV-Vis及HPLC对前体药物释放情况进行检测分析。 5-Fluorouracil(5-Fu), commonly known as a broad-spectrum antineoplastic drug, has been widely used in the treatment of various kinds of cancer including colon cancer for 40 years. However, this antitumor agent exhibits serious adverse effects, such as their marrow toxicity, gastrointestinal reaction and low selectivity in their clinical use. In order to improve its antitumor activity and reduce its toxicity, the compound was modified in various ways, including the formation of conjugated prodrugs with kinds of carrier, microsphere and nanoparticles etc. Cyclodextrins(CDs) are known to be barely capable of being hydrolyzed and only slightly absorbed in passing through the stomach and small intestine; however they are fermented into small saccharides by colonic microflora and thus absorbed as small saccharides in the large intestine. This biodegradation property of CDs may be useful as a colon-targeting carrier, and thus CD prodrugs may serve as a source of site-specific delivery of drugs to colon. It was demonstrated that prodrugs of CDs can provide a versatile means for construction of not only colon targeted delivery systems, but also delayed release systems. 5-Fluorouracil was taken as a model drug and β-CD as the carrier in this study. Series prodrugs of 5-FU was prepared through the preparation of reactive 5-FU derivatives containing carboxyl group and coupling to hydroxyl groups of CD. The structures of the conjugates were charactered by using IR, UV–vis, ESI-MS, 1H, 13C-NMR spectra, elemental analyses, and thermal analysis. In vitro hydrolysis behavior in aqueous solution and in rat gastrointestinal tract contents of the conjugates were also investigated. The main content of this dissertation includes following aspects: 1. The preparation of 5-FU derivatives containing carboxyl group: 5-Fluorouracil- acetic acid(FUAC)、3-(5-FU-1)-propionic acid (FUPC)、and 5-(5-FU-1)-valeric acid(FUVC). 2. The coupling of 5-FU derivatives to β-CD: 5-FU was selectively conjugated onto the primary or secondary hydroxyl groups of β-CD through an ester linkage, by the substitution of 6-OTs-β-CD and the activated ester method respectively. For the secondary face conjugation, the degree of substitution(DS) can be controlled by changing the mole ratio of the starting materials(FUAC and β-CD). 3. In vitro release behavior of the conjugates in aqueous solution and in rat gastro- intestinal tract contents of the conjugates were investigated, and the reaction was monitored and analyzed by using UV-Vis and HPLC methods.

环糊精衍生物的设计、合成及其对环辛烯光异构化研究

环糊精(Cyclodextrins, CDs)经化学修饰后可以得到各种类型的衍生物，不仅可以扩展其原有的键合能力，而且还可以改变其选择性，是当代超分子化学的一个研究热点。环糊精第二面的仲羟基比第一面的伯羟基有着更好的催化性能，第二面的选择性修饰将产生更多有价值的衍生物，可用于催化、酶模拟、手性识别等方面。 取代苯甲酰基修饰环糊精对顺式环辛烯(cis-cyclooctene)光异构化反应有非常重要的影响作用，苯环上取代基的性质和取代位置与产物的%ee值和对映体构型之间存在某种内在联系。有目的地选择适宜取代基，设计、合成新型环糊精光增感剂, 有可能按预定目的得到更高%ee值的反式环辛烯；同时，取代苯甲酰基修饰环糊精对cis-cyclooctene光异构化的增感机理有待于进一步阐明。 本论文工作对环糊精的化学修饰以及超分子体系对cis-cyclooctene不对称光异构化反应方面的进展进行了调研。合成了一系列单-6-位取代苯甲酰基修饰环糊精，用于cis-cyclooctene光异构化增感反应，并用圆二色光谱滴定法研究这些环糊精衍生物与cis-cyclooctene的相互作用，以探索光增感反应机理。在此基础上，探讨了环糊精第二面的选择性修饰方法。内容主要包括： 1. 简要介绍了超分子化学的概况，并对环糊精的选择性修饰方法和超分子体系对cis-cyclooctene不对称光异构化反应的主要成果和最新进展进行了评述。 2. 合成了12种单-6-O-(取代苯甲酰基)-β-环糊精，其中10种为新化合物。采用紫外光谱、红外光谱、核磁共振波谱以及质谱等手段对化合物的结构进行了表征。 3. 探索了直接选择性修饰环糊精第二面的便捷新方法。用取代苯甲酰咪唑酯为酰化试剂，0.2M碳酸盐缓冲溶液(pH=9.9)作催化剂，能够有效地活化2-位仲羟基，对环糊精第二面进行选择性修饰，此方法既简便又经济；同时，发现取代苯甲酰基能够在β-CD第二面的2-位、3-位羟基间相互迁移。 4. 用单-6-O-(取代苯甲酰基)-β-环糊精作光增感剂，对cis-cyclooctene光异构化反应进行研究。实验结果证明：取代苯甲酰基上的取代基性质、位置、长度对反应的对映选择性有很大影响；此外，反应体系溶剂极性对产物的%ee值和对映体构型也有重大影响。用单-6-O-(3-甲氧苯甲酰基)-β-CD作增感剂，cis-cyclooctene光异构化反应产物(R)-trans-cyclooctene的对映选择性为45.8%ee，是到目前为止取得的最好对映选择性。 5. 采用圆二色光谱滴定法研究环糊精衍生物与cis-cyclooctene的相互作用，计算包结物的平衡常数，研究包结物的相对稳定性，为探索光增感反应机理提供基础。我们猜测：电子效应对cis-cyclooctene光异构化反应的影响，可能比取代基位置对反应的影响更大，借助电子效应有希望获得更高的%ee值。 Cyclodextrins can be subjected to diverse modifications to give a wide variety of cyclodextrin derivatives, which could not only extend their original molecular binding ability, but also alter their molecular selectivity. Therefore, cyclodextrin chemistry is currently a significant topic in supramolecular chemistry. The more open secondary hydroxyl side of CDs is stated to be catalytically very important, modifications of this face are believed to produce valuable derivatives for catalysis, enzyme mimic, chiral discrimination, etc. Mono-6-O-(substituted benzoyl)-β-CDs as novel supramolecular photosensitizing hosts have recently excited considerable attention in photochirogenesis. The supramolecular photosenstization of cis-cyclooctene mediated by them gave chiral trans-cyclooctene, enantiomeric excess of which was critically affected by the substituent introduced to the sensitizer moiety. In order to enhance the photoenantiodifferentiating ability, and elucidate the origin mechanisms of substituent-dependent enantioselectivity, in this work a series of mono-6-O-(substituted benzoyl)-β-CDs have been synthesized, and applied for enantiodifferentiating photoisomerization of cis-cyclooctene. The major contents are as follows: 1. The general aspects of supramolecular chemistry were descibed briefly. The new progress and important achievements on methods of selective modification of cyclodextrin and supramolecular enantiodifferentiating photoisomerization of cis-cyclooctene were reviewed. 2. Twelve mono-6-O-(substituted benzoyl)-β-CDs including ten novel compounds have been synthesized. Their structures have been characterized by using UV-vis, IR, NMR and MS methods. 3. A new convenient strategy for direct acylation of β-cyclodextrin on the secondary hydroxyl face was achieved by using the combination of N-benzoylimidazole and carbonate buffer in DMF, and the acyl migration between the C-2 and C-3 hydroxyl groups of β-cyclodextrin was found. 4. Experiments using mono-6-O-(substituted benzoyl)-β-CDs as chiral sensitizing hosts for mediating the enantiodifferentiating photoisomerization of cis-cyclooctene, were carried out. The results indicate that enantiomeric excess was critically affected, or even switched in sign, by the substituent introduced to the sensitizer moiety, and polarity of solvent. Using mono-6-O-(3-methoxybenzoyl)-β-CD as chiral sensitizing host, (R)-trans-cyclooctene was obtained in up to 45.8% enantiomeric excess, which is the highest value ever reported for supramolecular photochirogenesis with analogous hosts. 5. The conformational variation of these modified CDs and their complexation behaviors with cis-cyclooctene were examined by circular dichroism spectroscopy in water-methanol mixed solvents, which reveal that the orientation of chromophore was highly sensitive to the type, position and length of the introduced substituents. In the end, the complex stability constants(Ks) were calculated, and the mechanisms of reaction were discussed. Maybe, electronic effects are more important than positions of substituents for mediating the enantiodifferentiating photoisomerization of cis-cyclooctene.

改进的SILAR法制备ZnO薄膜及其表征

A modified solution method, successive ionic layer adsorption and reaction(SILAR), was applied to prepare transparent zinc oxide(ZnO) film on glass substrate at (125±5) ℃ in mixed ion precursor solution. The surface morphology and crystallizations of films were analyzed by field emission scanning microscopy(FESEM) and X-ray diffraction(XRD), respectively. The optical properties of the films were studied by ultraviolet visible(UV-Vis)spectroscopy. The results show that the obtained samples are polycrystallin...中文文摘：采用一种改进的液相成膜技术——连续离子层吸附与反应(SILAR)法,用锌氨络离子[Zn(NH3)4]2+溶液作为独立的前驱体溶液,以载玻片为衬底,在(125±5)℃的温度下沉积出致密、透明的ZnO薄膜。分别用冷场发射型扫描电镜(FESEM)和X射线衍射(XRD)分析了薄膜样品的表面形貌和结晶状态,用紫外-可见分光光度计(UV-Vis spectroscopy)研究了薄膜样品的发光性能。结果表明:获得样品为六角纤锌矿结构的多晶薄膜材料沿[002]方向择优生长;样品表面均匀、致密,厚度约为550nm;在可见光波段具有高的透射率(>80%)。

改进的SILAR法制备ZnO薄膜及其表征

采用一种改进的液相成膜技术——连续离子层吸附与反应(SILAR)法,用锌氨络离子[Zn(NH3)4]2+溶液作为独立的前驱体溶液,以载玻片为衬底,在(125±5)℃的温度下沉积出致密、透明的ZnO薄膜。分别用冷场发射型扫描电镜(FESEM)和X射线衍射(XRD)分析了薄膜样品的表面形貌和结晶状态,用紫外-可见分光光度计(UV-Vis spectroscopy)研究了薄膜样品的发光性能。结果表明:获得样品为六角纤锌矿结构的多晶薄膜材料沿[002]方向择优生长;样品表面均匀、致密,厚度约为550nm;在可见光波段具有高的透射率(>80%)。

金纳米线阵列制备及其光谱特性

利用电化学沉积方法在重离子径迹模板中制备出直径从45nm到200nm,长径比达700的金纳米线阵列,利用扫描电子显微镜(SEM)和X射线衍射(XRD)对所制备金纳米线的形貌及晶体结构进行分析,结果表明,在1.5V(无参比电极)沉积电压下所制备出的直径为200nm金纳米线沿[100]晶向具有较好择优取向.利用紫外-可见光谱(UV-Vis)对镶嵌在透明模板中平行排列的金纳米线阵列光学特性进行研究,发现金纳米线直径为45nm时,其紫外可见光谱在539nm处有强烈吸收峰,随着金纳米线直径增加,吸收峰红移,当金纳米线直径达到200nm时,其吸收峰峰位移至700nm.结合金纳米颗粒相关表面等离子体共振吸收效应对实验结果进行了讨论.

重离子径迹模板法电化学制备聚吡咯纳米线

采用蚀刻的聚碳酸酯(PC)离子径迹膜为模板,结合电化学沉积技术,制备出了直径为100~320 nm、长度从几μm到30μm的聚吡咯纳米线。利用场发射扫描电子显微镜(FESEM)、透射电子显微镜(TEM)对纳米线的形貌进行了表征。结果表明,所制备出的聚吡咯纳米线均呈圆柱形,且表面光滑、粗细一致。聚吡咯纳米线的紫外-可见(UV-Vis)光谱分析表明,随着聚吡咯纳米线直径增加,聚吡咯纳米线吸收峰展宽,且峰位向长波方向移动。

2.1GeV Kr离子在聚碳酸酯膜中引起的辐照效应研究

用傅立叶变换红外光 (FTIR)谱仪和紫外 /可见光 (UV/VIS)谱仪研究了2 1GeVKr离子在聚碳酸酯 (PC)膜中产生的效应 .研究结果表明 ,在高能Kr离子辐照下 ,PC膜中发生了断键、断链和键的重组 ,炔基的出现是键的断裂和重组的结果 .这些效应与辐照剂量和电子能损有关 .辐照也使PC膜中发生了从氢化非晶态碳向非晶态碳的转变 ,在UV/VIS中 ,波长为 3 80 ,4 50和 50 0nm处的相对吸光度随能量沉积密度的增加近似按线性变化

The annealing behavior of Cu nanoparticles in Ar-ion implanted spinel

Magnesium aluminate spinel crystals (MgAl2O4 (1 1 0)) deposited with 30 nm Cu film on surface were implanted with 110 key Ar-ions to a fluence of 1.0 x 10(17) ions/cm(2) at 350 degrees C, and then annealed in vacuum condition at the temperature of 500, 600, 700, 800 and 900 degrees C for 1 h, respectively. Ultraviolet-visible spectrometry (UV-VIS), scanning electron microscopy (SEM), Rutherford backscattering (RBS) and transmission electron microscopy (TEM) were adopted to analyze the specimens. After implantation, the appearance of surface plasmon resonance (SPR) absorbance peak in the UV-VIS spectrum indicated the formation of Cu nanoparticles, and the TEM results for 500 degrees C also confirmed the formation of Cu nanoparticles at near-surface region. In annealing process, The SPR absorbance intensity increased at 500 and 700 degrees C, decreased with a blue shift of the peak position at 600 and 800 degrees C, and the peak disappeared at 900 degrees C. The SPR absorbance intensity evolution with temperature was discussed combined with other measurement results (RBS, SEM and TEM). (C) 2010 Elsevier B.V. All rights reserved.