A spectroscopic study on the 12-heteropolyacids of molybdenum and tungsten (H3PMo12−nWnO40) combined with cetylpyridinium bromide in the epoxidation of cyclopentene

The epoxidation of cyclopentene with hydrogen peroxide catalyzed by 12-heteropolyacids of molybdenum and tungsten (H₃PMo_12−nW_nO₄₀, n = 1–11), 12-tungstophosphoric acid and 12-molybdophosphoric acid combined with cetylpyridinium bromide as a phase transfer reagent was carried out in acetonitrile. Among 13 heteropolyacids investigated, catalyst of H₃PMo₆W₆O₄₀ showed the highest activity, giving a conversion of 60% and a selectivity of 95% in the epoxidation of cyclopentene. The fresh catalysts and the catalysts under reaction condition were characterized by UV–vis, FT-IR and ³¹P NMR spectroscopy, which has revealed that all of the molybdotungstophosphoric acids were degraded in the presence of hydrogen peroxide to form a considerable amount of phosphorus-containing species. The active species resulted from H₃PMo₆W₆O₄₀ are new kinds of phosphorus-containing species, which is different from {PO₄[WO(O₂)₂]₄}³⁻.     

拓扑指数法研究显色剂结构与反应性能关系

本文讨论了２９个不对称色酸双偶氮膦酸型显色剂的分子联接性指数，并将其与结构选择性因子相结合，用于偶氮类剂结构与铈显色反应灵敏度的相关性研究，讨论了显色剂结构对显色反应灵敏度的影响。     

高碲酸合铜（Ⅱ,Ⅲ）配合物的合成和性质

在Ｈ６ＴｅＯ６／ＫＯＨ水溶液中以臭氧为氧化剂，将二价铜化合物氧化成三价铜化合物，并获得一个新的三价铜化合物Ｂａ４Ｋ［Ｃｕ（Ｈ２ＴｅＯ６）２］（ＯＨ）４．６Ｈ２Ｏ；描述了碱性溶液中“Ｃｕ（Ⅲ）／Ｃｕ（Ⅲ）”循环伏安图。对铜（Ⅲ）化合物，Ｎａ４Ｈ［Ｈ２ＴｅＯ６）２］．１７Ｈ２Ｏ以及相应的铜（Ⅱ）配合物的电子光谱和Ｃｕ２ｐＸＰＳ进行了研究，给出了其配位场场强参数和Ｃｕ２ＰＸＰＸ的电子结合能。由于价态升高     

双波长吸光光度法测定磷矿中氧化镁

以EGTA－Ba和SO4^2-为联合掩蔽体系，有效地消除因大量钙存在而产生的干扰。在PH10．2硼砂缓溶液中，镁与偶氮氯磷Ⅰ形成稳定络合物，用自制的双波长分光光度仪，在组合波长570nm和500nm下，用于磷矿中镁的测定。不需分离，方法简单，快速，结构满意。     

[α-(2-氧代烷基)-α-(取代苯胺基)甲基苯基]-β-D-吡喃阿洛糖苷的合成及镇静活性研究

以豆腐果苷为原料, 通过Mannich反应与取代苯胺和脂肪酮共合成了七个豆腐果苷衍生物, 均未见文献报道. 其结构经¹H NMR, IR, MS和HRMS确认, 并进行了药理活性筛选. 结果表明, 部分化合物均具有良好的镇静活性. 其中, 化合物2a (200 mg/kg), 2b (200 or 100 mg/kg)和2e (200 mg/kg)与豆腐果苷相比较, 具有更强的疗效.     

Comparison of the thermal behavior of three cellulose fibers mercerized or submitted to solar degradation

Comparison of Lyocell, modal and viscose fibers was performed by means of differential scanning calorimetry, thermogravimetry and scanning electron microscopy. Thermal analysis was performed in air atmosphere. Samples were mercerized (21.3 g 100 mL-1) or submitted to solar radiation (seven months). Solar degraded samples presents a higher thermal stability and are initially less degraded. Furthermore, Lyocell fiber is the most stable under thermal degradation conditions. Heating produces a reduction of the fiber diameter (about 50%). This revised version was published online in July 2006 with corrections to the Cover Date.     

Facile cyclic ammonium salt with the smallest size for high performance electric double layer capacitors

A novel cyclic ammonium salt, N,N-dimethylpyrrolidinium tetrafluoroborate (P₁₁-BF₄), was successfully synthesized for the first time. The smallest cyclic structure of P₁₁-BF₄ induced high solubility and conductivity in PC, which can easier enter the micropores of activated carbon and occupy more surface area during charge/discharge process.     

The recent progress of wide bandgap donor polymers towards non-fullerene organic solar cells

The recent progress of wide bandgap (WBG) donor polymers for non-fullerene polymer solar cells (NF-PSCs) were reviewed in detail, which was classified by D-type and D-A type molecular backbones to discuss the related structure-property correlations and put forward an outlook for future innovations.