配合物聚合反应研究──Ⅱ.以二氨基磺磷酸盐配合物合成聚脲

以二氨基磺酸盐配合物合成了一系列主链上合金属元素(Ca,Ni,Co,Cu)的聚脲聚合物。用IR和1HNMR对其结构进行了表征,以TG-DTA研究了其热性能,并讨论了金属元素种类及其含量对聚脲聚合物溶液粘度的影响。     

甲醇在欠电位沉积Ru修饰Pt电极上的催化氧化

采用欠电位沉积(upd)方法在Pt 表面沉积亚单层的Ru制备出upd-Ru/Pt 电极. 通过欠电位沉积前后电极在0.5 mol·L-1 H2SO4溶液中循环伏安图-152 - 128 mV(vs Ag/AgCl)电位范围内对氢区的数值积分确定Pt表面Ru 的覆盖度. 用电化学方法测试了甲醇在upd-Ru/Pt电极上的催化氧化, 并讨论分析了欠电位沉积电位和Ru的表面覆盖度对甲醇氧化的影响. 结果表明, Ru能够欠电位沉积到Pt表面. Pt表面欠电位沉积少量的Ru 即能大大促进甲醇的氧化.只要控制upd-Ru的沉积量, upd-Ru原子就能大大促进甲醇氧化而与沉积电位无关. Ru原子对甲醇氧化的促进作用与Ru和Pt是否形成合金无关, 而取决于Ru 在Pt表面的百分含量.     

负载型双噁唑啉催化剂上的不对称Diels-Alder反应

 分别以乙烷桥键磺酸官能化的有机-无机杂化介孔材料、十二钨磷酸铯、活化硅胶以及SBA-15为载体,通过非共价键作用制备了负载型双噁唑啉催化剂,并将该催化剂用于催化3-((E)-2-丁烯酰基)-1,3-噁唑啉-2-酮和环戊二烯的不对称Diels-Alder反应. 研究表明,催化剂的性能取决于载体本身以及载体表面阴离子的性质. 以SBA-15为载体时产物的对映体选择性较低,可归因于载体表面较低的羟基浓度.     

Self-assembly and characterization of paclitaxel-loaded N-octyl-O-sulfate chitosan micellar system

N-octyl-O-sulfate chitosan micellar system loaded paclitaxel was prepared by using dialysis method. The critical micelle concentration (CMC) of the modified chitosan was found to be 0.45 mg/ml. Compared with the amount of N-octyl-O-sulfate chitosan, the paclitaxel loading amount in the system was up to 25% (w/w), depending on both of the solvents used in dialysis and the feed weight ratio of paclitaxel to the derivative. The polymeric micelles forming and loading occurred simultaneously in the dialysis process when ethanol and water were utilized as the solvents for paclitaxel and the polymer, respectively. Paclitaxel-loaded micellar system of N-octyl-O-sulfate chitosan was characterized by DSC, WXRD and TEM. TEM photograph revealed that paclitaxel existed as the colloid particulates in ethanol before loading and in the cores of the spherical polymeric micelles after loading. The results of DSC and WXRD indicated that paclitaxel was transferred from the crystalline state to amorphous state after loading. The lyophilized powder of micellar system (25% (w/w) loading) could be reconstituted easily in aqueous media even after 2 months storage at 4 degrees C without the change of paclitaxel entrapment and micelle size. The reconstituted solution (2.1 mg paclitaxel/ml) also showed good stability. The dilution with saline may decrease the loading and physical stability based on the dilution times which was related with CMC of the polymer. In vitro tests showed that paclitaxel was slowly released from micellar solution and the release lasted up to 220 h by means of the dialysis method.     

Synthesis of persulfate containing poly (N-vinyl-2-pyrrolidone) (PVP) hydrogels in aqueous solutions by γ-induced radiation

The effect of ⁶⁰Co γ-irradiation on aqueous solutions of poly(N-vinyl-2-pyrrolidone) (PVP) in the presence of persulfate anion has been investigated. The gelation dose of PVP and persulfate containing PVP aqueous solutions has been determined. At low concentrations of persulfate (1.00–3.50%), gelation percentages exhibited a decreasing trend by increasing persulfate content in aqueous solutions of the polymer. The gelation doses of persulfate containing polymer solutions were calculated by the Charlesby–Pinner equation. It was observed that the gelation dose values were shifted to higher values by increasing persulfate concentration in solution. The ratio of the chain scission and crosslinking yields (G(s)/G(x)) was also determined. The results showed that the G(s)/G(x) ratios were smaller than one for PVP aqueous solution system, whereas those obtained for persulfate containing PVP aqueous solutions were higher than unity. The results implied that the chain scission of polymer is more effective than crosslinking in the presence of persulfate. Mechanism of the crosslinking and/or degradation and structure–property relationship of PVP and PVP/persulfate hydrogel systems were investigated by Fourier transformation infeared and thermal analysis (differential scanning calorimetry, thermal gravimetric analysis and differential thermai analysis) methods.     

An extended two‐dimensional copper–molybdate compound with mixed dicarboxyl and organodiamine ligands

The title complex, poly[di‐μ₃‐oxo‐hepta‐μ₂‐oxo‐tetra­oxo­bis(1,10‐phenanthroline)‐μ₄‐terephthalato‐dicopper(II)­tetra­molybdate(VI)], [Cu₂Mo₄(C₈H₄O₄)O₁₃(C₁₂H₈N₂)₂], represents a novel two‐dimensional copper–molybdate compound with mixed ligands. Tetra­nuclear molybdenum oxide clusters are joined through corner‐sharing into a ribbon‐like chain, with [Cu(phen)]²⁺ (phen is 1,10‐phenanthroline) complexes grafted onto either side. The terephthalate ligand lies about an inversion centre and links these chains to form a layer via Cu—O and Mo—O bonds. Face‐to‐face π–π stacking inter­actions between adjacent phen ligands stabilize the structure.     

5，10，15，20-四 [4-(4''-乙基哌嗪基)苯基]卟啉的合成及其与DNA的相互作用

基于卟啉对癌细胞的特殊亲和作用和哌嗪化合物的抗肿瘤、抗病毒作用，设计并合成了具有哌嗪结构的新型卟啉化合物5，10，15，20-四[4-(4'-乙基哌嗪基)苯基]卟啉（TEPPPH₂），其结构经UV-Vis, 元素分析，¹H NMR等手段证明。采用UV-Vis光谱和荧光光谱研究了TEPPPH₂和小牛胸腺DNA 的相互作用模式和结合机理。实验发现，TEPPPH₂能嵌入到DNA的碱基对中，1个小牛胸腺DNA分子对TEPPPH₂分子的最大结合数n约为88，结合常数为8.4×10⁶mol•L^-1 。TEPPPH₂与DNA的结合数和结合常数大于已知的四（4-N-甲基吡啶基）卟啉和Ca/sal-his、Ni/sal–aln型席夫碱抗癌药物。     

ZnHZSM-5上丙烷芳构化的研究-丙烷的活化

研究了HZSM－5、ZnHZSM－5和ZnNaZSM－5上的羟基振动光谱和一氧化碳吸附的红外光谱，以及丙烷的芳构化反应．红外光谱中发现表征强B酸的3610cm－1羟基振动峰相对强度由于锌离子的引入和浸渍氢氧化钠而减小，说明了锌离子和钠离子均进入了分子筛的阳离子位；一氧化碳在锌离子上的吸附峰位在2232cm－1，说明进入阳离子位的锌离子是一种强L酸．反应结果表明，锌离子的引入大大地促进了丙烷的转化和芳烃选择性的提高；在一定范围内，随浸渍氢氧化钠量的增加，丙烷转化率下降，而丙烯的选择性和产率增加，说明了锌组份直接参与了丙烷的脱氢过程．Zn－L酸是丙烷活化脱氢的中心，丙烷在该中心上异裂活化直接脱氢．