含碲唑杂环部花青的性能研究

本文报道了由新型杂环苯并碲唑衍生的4个染料中间体以及三种类型共6个部花青。染料合成的条件依酸性酮亚甲基核而异。研究了染料吸收光谱的溶剂效应, 发现极性较弱的罗丹宁部花青随着溶剂极性增大呈现吸收峰的显著红移, 而极性较强的双甲酮及巴比妥酸部花青的吸收则显示一定程度的蓝移。利用共振理论解释了上述现象。同时发现具有相似溶剂效应的两种部花青的转移能量(E~T)图呈现很好的线性关系, 有可能用作溶剂极性的指示剂。     

含碲唑杂环部花青的合成

含碲唑杂环部花青的合成罗学红，刘秀芳，徐汉生（武汉大学化学系，４３００７２）部花青（又称份菁，ｍｅｒｏｃｙａｎｉｎｅｓ）是一类重要的功能染料。它不仅可以作为感蓝或感绿的光谱增感剂应用于照相化学领域￣［１］，也可作为光盘染料用于其它信息记录￣［２］。这...     

N-(β-氨基-4-氯桂皮酰基)仲丁胺类化合物的合成

刘维勤等曾研究β位取代桂皮酰胺类化合物的抗惊厥活性.为了深入研究β位取代基位阻效应对桂皮酰胺类化合物抗惊厥活性的影响,我们合成了-系列N-(β-氨基-4-氯桂皮酰基)仲丁胺类化合物. 在氢化钠存在下,对氯苯乙酮与碳酸二乙酯缩合,生成对氯苯甲酰基乙酸乙酯.后者经水解、酸化得相应的羧酸.羧酸在室温下用草酰氯进行酰氯化,然后用仲丁胺氨解,得到N-(β-羟基-4-氯桂皮酰基)仲丁胺(3)     

邻氨基二苯醚类重氮盐的水解及分子内缩合反应

用邻氨基二苯醚类化合物进行重氮化水解反应制备邻羟基二苯醚类化合物, 对影响氯代邻氨基二苯醚重氮盐水解反应和分子内关环反应的因素进行了系统研究, 讨论了取代基、金属及其离子催化等对两类反应的影响规律, 揭示了在金属离子催化下, 邻氨基二苯醚类化合物重氮盐发生分子内关环反应的规律, 并推测了反应机理.     

水相中可见光催化腈合成苯并咪唑衍生物

报道了在水相中可见光下1,2-苯二胺与苯腈的环化反应,合成了一系列苯并咪唑类化合物.反应用便宜、易处理、对环境无污染的曙红Y作为光催化剂.室温下在水相中反应,获得的产物有较好收率,最高产率可达到91%.提供了一种合成苯并咪唑类化合物的简便经济的方法.     

全二维气相色谱/飞行时间质谱(GC×GC/TOFMS)用于烟叶中挥发、半挥发性碱性化合物的组成研究

建立了烟叶中挥发性、半挥发性碱性化合物组成研究的全二维气相色谱/飞行时间质谱(GC×GC/TOFMS)分析方法, 并用所建立的方法对香料烟中碱性化合物进行了表征. 对比了一维气相色谱和全二维色谱方法用于烟叶碱性组分组成分析的效果. 一维色谱质谱方法共鉴定出45种碱性化合物. 用所建立的全二维气相色谱方法, 采用TOFMS谱图库检索结合全二维特有的包含结构信息的二维谱图, 通过族分离和结构谱图鉴定, 鉴定出了香料烟中挥发性、半挥发性碱性组分共92种. 包括吡咯类化合物6种, 吡啶类化合物39种, 吡嗪类化合物10种, 苯胺类化合物11种, 喹啉类化合物11种, 吲哚类4种和其他类化合物11种. 同时对不同类别的化合物在二维气相色谱上的分布模式进行了研究. 研究结果表明, 全二维色谱飞行时间质谱的高分辨率和特有的定性手段适合于烟叶这类复杂植物体系的化学组成研究.     

二苯并呫吨类化合物的环氧化反应研究

研究了二苯并呫吨类化合物的环氧化反应条件, 在室温、碱性条件下, 用廉价的H₂O₂作为环氧化剂对二苯并呫吨类化合物进行环氧化, 产率高达91%～98%, 是一种简便合成环氧二苯并呫吨类化合物的方法.     

气相色谱法检测汤中氯丙醇类化合物

应用毛细管柱-气相色谱法测定汤料中氯丙醇类化合物.汤料试样中氯丙醇类化合物在索氏抽取器中用乙醚萃取,于萃取液中通入氮气吹干乙醚,残留物用每次1 mL甲醇萃取两次以净化氯丙醇类化合物.收集并合并甲醇萃取液,蒸发除去甲醇后用N,O-双(三甲基硅烷)-三氟乙酰胺进行衍生化,所得衍生物经毛细管色谱柱分离,用氢火焰离子化检测器(FID)检测,方法的检出限为0.01 mg·kg-1.对精密度及回收率作了试验,得到的回收率在95%～102%之间,RSD(n=5)值小于4.5%.     

酪氨酸与1-亚硝基-2-萘酚反应的研究

本文用荧光、分子吸收光谱和电化学等方法研究了在含 Na NO2 的 HNO3溶液中酪氨酸与 1 -亚硝基 - 2 -萘酚的反应 ,该反应最后生成具有荧光性质的酚噻嗪类化合物。于 - 0 .5 3V( vs. SCE)处被还原的反应中间物酚噻嗪类化合物的氧化物可被光还原为酚噻嗪类化合物 ,其分解过程的反应为二级反应 ;反应速度常数为 5× 1 0 - 4L· mol- 1· min- 1。酚噻嗪类化合物的生成过程为一级反应 ,反应速度常数为 0 .0 2 1min     

基于烯基叠氮合成含氮杂环化合物的研究进展

自1910年首次被报道以来,烯基叠氮类化合物受到了化学工作者们广泛的关注.作为一类重要的有机合成中间体,尤其是在过渡金属催化下合成氮杂环类化合物方面,烯基叠氮类化合物有着广泛的应用.主要综述了烯基叠氮类化合物在构建含氮杂环化合物领域的研究进展.     

Crown-containing spironaphthoxazines and spiropyrans. 3. Synthesis and investigation of the merocyanine form of crown-containing spirobenzothiazolinonaphthoxazine

A method for the synthesis of the spirobenzothiazolinonaphthoxazine, stable in the merocyanine form and containing a crown-ether fragment was developed. The complexing properties of the prepared merocyanine compound and the spectroscopic and photochromic characteristics of its complexes with alkaline earth metal cations were studied by NMR and UV spectroscopy. The results were analyzed using quantum-chemical calculations. The addition of alkaline earth metal perchlorates to a solution of a crown ether-containing merocyanine dye in MeCN results in the coordination of metal cations to two binding centers, namely, the crown-ether fragment and the merocyanine oxygen atom. This gives rise to two types of complexes, which differ substantially in their structurally. The complexation induces changes in the UV spectra and influences on the photochromic behavior of the prepared compound.     

The time-resolved spectra of a crowned indolinospiroben-zopyran

The photochromic process of an indolinospiropyran with a crown ether fragment (BN-BIPS) was studied by nanosecond laser photolysis technique. The results show that quinonic merocyanine B was formed via an excited singlet state from BN-BIPS; in acetonitrile solution, the transient absorption of merocyanine B showed an obvious decay while a new transient absorption at 440nm (from isomer C) was observed simultaneously. The decay of merocyanine B and the formation of isomer C (at 440nm) were accelerated in the presence of alkali metal cation. In contrast, the formation of isomer C was not observed in spiropyran without a crown ether fragment: BIPS.     

A multiswitchable poly(terthiophene) bearing a spiropyran functionality: understanding photo- and electrochemical control

An electroactive nitrospiropyran-substituted polyterthiophene, poly(2-(3,3'-dimethylindoline-6'-nitrobenzospiropyranyl)ethyl 4,4'-didecyloxy-2,2':5',2'-terthiophene-3'-acetate), has been synthesized for the first time. The spiropyran, incorporated into the polymer backbone by covalent attachment to the alkoxyterthiophene monomer units, leads to multiple colored states as a result of both photochemical and electrochemical isomerization of the spiropyran moiety to merocyanine forms as well as electrochemical oxidation of the polyterthiophene backbone and the merocyanine substituents. While electrochemical polymerization of the terthiophene monomer can take place without oxidation of the spiropyran, increasing the oxidation potential leads to complex electrochemistry that clearly involves this substituent. To understand this complex behavior, the first detailed electrochemical study of the oxidation of the precursor spiropyran, 1-(2-hydroxyethyl)-3,3-dimethylindoline-6'-nitrobenzospiropyran, was undertaken, showing that, in solution, an irreversible electrochemical oxidation of the spiropyran occurs leading to reversible redox behavior of at least two merocyanine isomers. With these insights, an extensive electrochemical and spectroelectrochemical study of the nitrospiropyran-substituted polyterthiophene films reveals an initial irreversible electrochemical oxidative ring-opening of the spiropyran to oxidized merocyanine. Subsequent reduction and cyclic voltammetry of the resulting nitromerocyanine-substituted polyterthiophene film gives rise to the formation of both merocyanine π-dimers or oligomers and π-radical cation dimers, between polymer chains. Although merocyanine formation is not electrochemically reversible, the spiropyran can be photochemically regenerated, through irradiation with visible light. Subsequent electrochemical oxidation of the nitrospiropyran-substituted polymer reduces the efficiency of the spiropyran to merocyanine isomerization, providing electrochemical control over the polymer properties. SEM and AFM images support the conclusion that the bulky spiropyran substituent is electrochemically isomerized to the planar merocyanine moiety, affording a smoother polymer film. The conductivity of the freestanding polymer film was found to be 0.4 S cm(-1).     

Inactivation of Photosensitizing Merocyanine Dyes by Plasma, Serum and Serum Components

Abstract— Merocyanine dyes with an oxygen in the electron donor heterocycle were rapidly degraded by plasma, serum and serum components. Replacement of the oxygen by a sulfur or selenium atom rendered the dyes refractory to degradation. The degradation of labile merocyanine dyes was temperature dependent and oxygen independent. The plasma component that was responsible for the degradation of merocyanine dyes was sensitive to heat and detergent, suggesting an enzymatic process. The identification of the structural requirements for sensitivity/resistance to degradation provides the experimenter with a simple means to manipulate the stability of mer-ocyanines in high serum or plasma environments and may expand the clinical utility of merocyanine photosen-sitizers beyond their traditional role in the extracorporeal purging of bone marrow grafts.     

Molecular design of tetraazamacrocyclic derivatives bearing a spirobenzopyran and three carboxymethyl moieties and their metal-ion complexing behavior.

Tetraazacyclododecane and tetraazacyclotetradecane derivatives bearing a spirobenzopyran and three carboxymethyl moieties, 1 and 2, and a diethylenetriamine derivative bearing a spirobenzopyran and four carboxymethyl moieties 3 were synthesized. The isomerization behaviors based on the spirobenzopyran moiety of these ligands were studied by UV-visible spectrophotometry in aqueous solutions containing various metal ions at neutral pH. These ligands formed stable 1:1 complexes with lanthanide ions, while the spirobenzopyran moiety was isomerized to its corresponding merocyanine form even under dark conditions. In aqueous solutions containing a lanthanide ion, the absorption spectra of 1 or 2 showed remarkable blue shifts, while absorbances at the maximum absorption wavelengths in the visible region were enhanced; such changes are attributable to the isomerization to the merocyanine form of the spirobenzopyran moiety. These results suggest that the phenolate anion of the merocyanine moiety interacts very strongly with a lanthanide ion bound by the complexing moiety because of the high charge density of lanthanide ions. In contrast, the absorbance of merocyanine form was decreased by the complexation of the macrocyclic ligand with transition metal ions, such as Cu2+ and Zn2+. This result indicates that macrocyclic ligands, 1 and 2, formed complexes with transition metal ions only by the aminocarboxylate moieties, and the phenolate ion of merocyanine moiety was not able to participate in the complexation. This conclusion was also demonstrated by density functional theory calculations.     

Crown-containing spironaphthoxazines and spiropyrans. 2. Influence of metal cations on the photochromic properties of spironaphthoxazines linked with aza-15(18)-crown-5(6) ethers

Spironaphthoxazines linked with aza-15(18)-crown-5(6) fragments were synthesized and studied for the first time. Addition of alkaline-earth cations to solutions of crown-containing spironaphthoxazines causes a hypsochromic shift of the absorption band of the spiro form and a bathochromic shift of the absorption band of the merocyanine form, shifts the equilibrium to the merocyanine form, and changes the lifetime of the photoexcited merocyanine form. The spectral and kinetic data were used to propose a mechanism of complexation and calculate the stability constants of the resulting complexes. The complexation involves the crown fragment and the merocyanine oxygen atom. The type of the complex is determined by the cation nature and size.     

Switching Properties of a Spiropyran–Cucurbit[7]uril Supramolecular Assembly: Usefulness of the Anchor Approach

A nitrospiropyran, which was modified with a cadaverine‐derived anchor, was investigated with respect to its thermally induced isomerizations, hydrolytic stability of the merocyanine form, and photochromic ring closure. The host–guest complexation of the anchor by the cucurbit[7]uril macrocycle, evidenced by absorption titration, NMR spectroscopy, and electrospray ionization mass spectrometry, produced significant improvements of the switching properties of the photochrome: 1) appearance of the merocyanine form about 70 times faster, 2) practically unlimited hydrolytic stability of the merocyanine (two and a half days without any measureable decay), and 3) fast, clean, and fatigue‐resistant photoinduced ring closure back to the spiro form. The importance of an adequate molecular design of the anchor was demonstrated by including control experiments with spiropyrans with a shorter linker or without such structural asset.     

光致变色冠醚部花菁染料的合成及其逆光致变色性

作者用含冠醚结构单元的2-甲基-苯并噻唑季铵盐与取代水物醛缩合得到了五个光致变色冠醚部化菁化合物。这些新的冠醚化合物具有逆光致变色性质, 较稳定的结构是开环部花菁式。     

Induction of Columnar and Smectic Phases for Spiropyran Derivatives: Effects of Acidichromism and Photochromism

Liquid‐crystalline (LC) properties have been induced in a number of spiropyran derivatives by the addition of methanesulfonic acid. Spiropyran derivatives containing one or two gallic acid moieties with one, two, or three long alkyl chains were prepared. Acid‐induced spiro–protonated‐merocyanine isomerization induced mesomorphism for these materials. Equimolar mixtures of methanesulfonic acid and the spiropyran derivatives with one or two dodecyloxy chains exhibited smectic A phases, whereas the spiropyran derivatives containing the gallic acid moiety with three dodecyloxy chains showed hexagonal columnar phases. On the contrary, photoirradiation of the spiropyran compounds in the bulk liquid state did not lead to the induction of mesomorphism, although the merocyanine form was induced. These results suggest that these merocyanine derivatives with ionic and nonionic moieties cannot simply form nanosegregated LC structures. Complex formation of the merocyanine form with methanesulfonic acid may play a key role in the formation of LC molecular assemblies.     

Synthesis and Photochromism of Crowned Spirobenzothiapyran: Facilitated Photoisomerization by Cooperative Complexation of Crown Ether and Thiophenolate Moieties with Metal Ions

Spirobenzothiapyrans bearing monoaza-12-crown-4, -15-crown-5, -18-crown-6, and oligooxyethylene moieties were synthesized, and their photochromism was examined in the presence of cations in acetonitrile. The cation complexation by their crown ether moieties cannot induce thermal isomerization to their corresponding colored merocyanine form, unlike the corresponding spirobenzopyran derivatives. The UV-light-induced isomerization was, however, facilitated by the cation complexation of the crown ether moieties and the affinity of the merocyanine thiophenolate anion to metal ions, especially in the presence of Li(+) and Ag(+). The presence of Ag(+) brought about the most remarkable effect in the facilitation of photoisomerization of the spirobenzothiapyrans and the thermal stability of the colored merocyanine form mainly due to the powerful interaction of the thiophenolate anion with the soft metal ion.