颜色的化学与物理学本质

从物质颜色及其影响因素出发,讨论了物质呈色的本质,对物质呈色的3要素及影响物体呈色的主要因素进行了论述,列举了自然界部分常见的颜色现象。通过对这些现象的分析,说明了物质的颜色与其结构、环境因素和人的视觉有着密切的关系。     

吡咯取代的俘精酸酐及俘精酰亚胺的光致变色反应研究

对6个吡咯取代的俘精酸酐和1个俘精酰亚胺的光致变色行为进行了研究,发现取代基的不同对它们的光致变色过程有显著的影响.稳态动力学分析表明,呈色体(7,7a-二氢吲哚衍生物,II)的光消色反应遵循一级动力学反应规律.取代基对光消色反应的速率常数有一定的影响,对于呈色体(II)而言,2-3-位上有取代基的化合物,其光开环反应的速率常数明显大于2-或3-位无取代基的化合物.对于俘精酸酐的光反应而言,其反应比较复杂,不符合简单的动力学级数.在呈色体(II)的2-或3-位引入给电子基团可以使7,7a-二氢吲哚衍生物的吸收光谱发生红移,化合物II7的最大吸收波长在乙腈中可达720nm.溶剂极性的增大,可以使是色体的吸收光谱发生显著的红移,而对俘精酸酐本身的吸收光谱影响甚微.     

氢气燃烧火焰颜色影响因素的研究及演示方案再设计

基于对氢气燃烧火焰颜色的不同解释,从焰色反应、火焰温度、气体流速等3方面影响因素设计方案进行实验研究,得出影响氢气火焰颜色的主要因素是气流速度、火焰温度及药品的焰色反应。巧用球形干燥管既控制气流速度、又控制火焰温度的特点,设计出可以观察到氢气燃烧火焰呈明显蓝色的演示装置。用可现取的仪器药品、可执行的实验方案、可重现的实验现象、可检验的实验结果,验证了教材中关于氢气燃烧火焰颜色的论述,突破了实际操作中氢气燃烧颜色不易观察的局限。     

改进硼化合物焰色反应的实验研究

研究了分别利用蒸发皿和粉笔进行硼化合物焰色反应的实验效果,重点研究了以粉笔作载体时,硼化合物用量、乙醇纯度和用量、浓硫酸用量等因素对硼化合物焰色反应的火焰高度、燃烧时间等的影响,并得出最佳实验条件。     

宝玉石的呈色机理

通过对宝玉石化学组成与吸收光谱的分析,阐述了宝玉石的呈色机理。红宝石、蓝宝石、翡翠的呈色是过渡金属离子（如铬、铁、钛等）d-d电子跃迁和电荷转移跃迁等因素共同作用的结果。红宝石和蓝宝石的颜色并不简单取决于铬或/和铁的含量,而更多取决于铁、钛间Fe2+/Ti4+和Fe3+/Fe2+的比值。翡翠的呈色是铁、铬、钒等过渡金属离子共同作用的结果。宝玉石的颜色也可能起因于其他过渡金属离子、色心等,从而使其色彩更加美丽。     

激发态分子内质子转移(ESIPT)发色团修饰的树枝形聚合物合成及光物理研究

设计合成了0～4代外围修饰激发态分子内质子转移(ESIPT)发色团的聚酰胺-胺树枝形聚合物G0～G4,化合物结构经过IR,1H NMR,13C NMR和MS表征.稳态光谱研究表明,树枝形聚合物在四氢呋喃溶液中形成了聚集体,发色团酮式发光随着化合物代数增大呈先增加后减小的变化.质子化树枝形聚合物G1-H～G4-H能溶于水,并在水中形成20 nm左右的聚集体,发色团在聚集体疏水区中构象受限,仅发射酮式发光,并且发光强度受树枝形聚合物分子大小的影响.     

(口恶)唑环取代的俘精酸酐的合成及其光致变色性能的研究

合成了含噁唑环的俘精酸酐,4-（5-甲基-2-对甲氧苯基-4-乙酰基嘿唑）乙叉（异丙叉）丁二酸酐,研究了该化合物在不同溶剂中的光致变色性能,进行了光成色和光消色过程的动力学研究,并考察了溶剂极性对该化合物吸收光谱的影响。稳态动力学分析结果表明,该化合物呈色体的光消色反应遵循一级动力学规律,俘精酸酐本身的光反应比较复杂,不符合简单的动力学级数。     

含席夫碱基的螺吡喃双功能光致变色材料的合成及性质

设计合成了一系列含席夫碱基的螺吡喃双功能光致变色材料4a~4n. 通过1H NMR, IR和HRMS对其结构进行了表征. 研究了化合物在几种溶剂和PMMA膜中的光致变色性质, 研究了化合物4a在甲醇中, 以及化合物4a和4f在高分子介质聚甲基丙烯酸甲酯(PMMA)中的消色过程. 结果表明, 化合物4e在PMMA膜中光照后呈现出与其它化合物不同的颜色, 为罕见的绿色. 化合物4a在二氯甲烷溶液中有良好的荧光性能. 所合成的新型含席夫碱基的螺吡喃双功能光致变色材料在甲醇、二氯甲烷和环己烷溶液中及在PMMA膜中均表现出良好的光致变色性质.     

2,2-二芳基取代萘并吡喃类光致变色化合物的合成与性能研究

从光消色速度和最大吸收强度两个角度出发, 用Grignard试剂和萘并吡喃-2|酮合成了一系列2,2-二芳基取代萘并吡喃类光致变色化合物, 并用 1H NMR, IR, MS和元素分析确定其结构. 研究了其紫外-可见光谱, 并探讨了紫外-可见光谱和光致变色性能之间的关系, 分析了其结构和光消色速度之间的关系, 初步探索到光消色速度快慢和取代基位置之间的规律, 为实用化的有机光致变色化合物的合成提供了有价值的参考依据.     

边缘保持滤波技术在空间色域映射中的应用

正色域映射是跨媒体图像复制中的一项关键技术,主要用以解决图像颜色信息在不同色域大小的颜色设备之间的准确传输。目前已有不少成熟的色域映射算法,其中,按照映射原理可以将色域映射算法分为逐点色域映射和空间色域映射两大类。逐点色域映射方法由于不考虑图像中像素间的颜色关系,因此会造成映射图像的细节丢失。空间色域映射方法考虑了每个映射点的空间颜色关系,是一种更为合理和更符合人类视觉特性的映射方法。但是,目前空间色域映射算法需要进行很多细节补偿,这将会产生视觉上较为明显的光晕效应。     

Some studies on the determination of indicator transition and its use in the titration of weak basic samples

In the titration of a weak basic sample, especially in the dilute solution, the transition color of the indicator is not sharp at the equivalence point. In order to avoid the indicator error, the color transition near the equivalence point must be known accurately. The color transition of an acid-base indicator can be calculated from complementary tristimulus data. To ensure accuracy, however, the chemical stoichiometric relationships about the acid-base equilibria are considered. A general expression for determination of the equivalence point is presented and factors influencing the titration are discussed.     

离子的极化和形变

离子的极化和形变是无机化学教学中的一对重要概念,这对概念可以用于解释化合物的结构及许多物理和化学性质。然而一些教科书在介绍这对概念时,大都把极化作用限于阳离子,把形变作用限于阴离子,而忽略了阴离子的极化作用和阳离子的形变作用。同时,在应用这对概念解释化合物结构和性质时,条理上也不十分清晰,甚至还出现自相矛盾的情况,使得学生在学习这对概念时感到困惑。本文介绍了离子的极化和形变这对概念的基本含义,讨论了影响极化能力和形变程度的因素,分析了一些化合物的结构以及溶解度、颜色和热稳定性等物理和化学性质。特别是对一些教学中有争议的问题给出了合理解释。在分析小分子结构时,极化和形变概念的运用可以弥补杂化轨道理论和价层电子对互斥理论的不足。     

稀土碘化物的合成及其发光性质的研究

本文将纯稀土金属与碘化汞在加温下合成了钪、镝、铒和铥的碘化物。并用DTA方法测定了NaI-ScI_3,NaI-DyI_3,NaI-ErI_3和NaI-TmI_3二元体系的相图,它们都是简单的有低共熔点的二元体系,但是后面三个体系在固相有相变,可能是形成了不稳定的化合物。文中还制造了填充不同比例的碘化钠和稀土金属碘化物混合物的金属卤化物灯,将它们的发光特性与汞灯进行了比较。碘化钠和稀土金属碘化物的加入能明显地改善灯的色温,显色性和光效。     

Crucial role of N...Si interactions in the solid-state coloration of disilylazobenzenes

2,2'-Bis(fluorodiphenylsilyl)azobenzenes bearing two methyl and butyl groups at the 4- and 4'-positions were synthesized, and their X-ray crystallographic analyses revealed that they have tetracoordinated and pentacoordinated silicon atoms, respectively. Although the two compounds showed almost the same spectra in solution, the reflectance spectra of the solid revealed that the pentacoordinated state had a weaker absorbance in the long-wavelength region compared with that of the tetracoordinated state, which is ascribed to the shift of the n-pi* transition. This difference in the absorptions due to the n-pi* transition drastically affects the color of the azobenzenes: the color of the pentacoordinated state becomes apparently paler than that of the tetracoordinated state.     

Role of metals and metal-deactivators in polymer degradation

The interaction between metals or metallic compounds and polymers is inevitable in the practical use of polymeric articles, and the stability of the polymers is often modified by these materials. Furthermore, the effect of the metallic compounds on the degradation of the polymers is extremely complicated, and is influenced by various factors.

This contribution deals with the possible role of metals or metallic compounds in the degradation of polymers, and this is followed by some typical examples of degradation by metallic compounds, mostly commercial pigments and transition metal compounds of stearic acid and acetylacetone, in typical commercial polymers. Recent studies of the inhibition of the copper-catalyzed thermo-oxidative degradation of polyolefins by deactivators, both commercial reagents and novel products, are discussed.     

基于C3v对称性的杯[6]芳烃对Hg2+的荧光选择性识别

合成了一系列具有C3v对称性、下缘分别利用Se、Te和S杂原子连接蒽环发光基团的杯[6]芳烃衍生物1-3.通过紫外-可见光谱和荧光光谱研究了它们对各种碱金属离子和过渡态金属离子的化学传感识别行为. 结果表明,含有Se杂原子的主体1在CH2Cl2溶液中对Hg2+表现出良好的选择性. 并且,通过肉眼可以直接观察到溶液颜色由无色变为黄色.通过荧光光谱的连续滴定实验,主体1-Hg2+体系的稳定常数可达（1.12 ? 0.08) ? 105 M-1. 因此,化合物1有望成为一种用于检测Hg2+的新型化学传感器.     

Recent advances in the field of diolefin polymerization with transition metal catalysts

Recent advances in the field of catalysis for 1,3-diene polymerization and in the interpretation of the polymerization mechanism are examined. Catalysts prepared from methylaluminoxanes and soluble transition metal compounds are in general more active than the analogous systems prepared from AlR₃. With some catalysts, however, (e.g. lanthanide systems) a high activity is obtained only when transition metal compounds containing preformed metal-carbon bonds are used. Methylaluminoxanes affect also the stereospecificity of the polymerization. Active and stereospecific systems are obtained from monocyclopentadienyl derivatives of Ti and aluminoxanes. Recent views on the factors that determine stereospecificity are examined. Schemes are presented for the formation of iso- or syndiotactic polymers, with 1,2, cis-1,4 or trans-1,4 structure, from various dienes.     

Mechanical force induced reversible fluorescence switching of two 3-aryl-2-cyano acrylamide derivatives

Two structural-simple 3-aryl-2-cyano acrylamide derivatives (CDPA-E and CDPA-P) were synthesized and characterized by NMR, MS, IR, and single crystal. It was found that both of them exhibited obvious piezofluorochromic properties. The as-prepared yellow-green compounds were both converted to orange-red after grinding with a spatula. All the ground samples can be recovered to its original color by heating at 80 °C over 5 min or fuming with solvents like DCM, ethanol, ethyl acetate etc. The changes in fluorescence color can be attributed to the phase transition between crystalline (order) state and amorphous (disorder) state according to the Powder XRD spectrum. At the molecular level, the extension of the conjugation length and the formation of excimers are confirmed to account for the color transition of CDPA-P and CDPA-E, respectively. In addition, CDPA-P exhibited AIE activity which was caused by the restricted rotation of the molecules in the crystal state.     

Interaction between the components of a five-component cold medicine

The reasons why five-component cold pills, a new complex medicine under development, change their color during shelf life are studied. The oxidation of ascorbic acid (AA) is responsible for the change in color; this process is enhanced in the presence of nitrogen base compounds. The IR spectra of equimolar mixtures of AA with some such compounds signify these changes. The results of this work can be used to eliminate undesired effects.