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1.
本文合成了三种含异噁唑二芳基乙烯光致变色化合物{1-(3,5-二甲基异噁唑-4-基),2-[2-甲基-5-(2-甲氧基苯基)噻吩-3-基]}全氟环戊烯(1o),{1-(3,5-二甲基异噁唑-4-基),2-[2-甲基-5-(3-甲氧基苯基)噻吩-3-基]}全氟环戊烯(2o)和{1-(3,5-二甲基异噁唑-4-基),2-[2-甲基-5-(4-甲氧基苯基)噻吩-3-基]}全氟环戊烯(3o),研究了取代基位置对三种化合物的UV/Vis光谱和荧光性质的影响。实验结果表明,化合物1–3具有良好的光致变色性质和荧光性质;取代基的位置对化合物的性质有显著影响。  相似文献   

2.
以2-甲基-3,5-二溴噻吩为原料通过溴代、suzuki偶合反应与全氟代环戊烯反应合成了1,2-双(2’-甲基-5’-(4-吡啶基)-3’-噻吩)全氟代环戊烯(BM-4-PTP),以IR,EA,ESI-MS和NMR进行合成产物的结构表征。通过扩散法用AgCF3COO和AgClO4与BM-4-PTP反应合成了两个Ag(I)配合物,用红外光谱进行表征。通过紫外光谱法研究了两个配合物在晶体相中的光致变色性质。结果表明:在合适波长的光激发下,伴随着在无色和紫色之间颜色的相互转换,配合物1和2在晶体相显示了可逆的光致变色反应,说明在晶体相两个配合物中的噻吩环均以反平行构型存在,二噻吩乙烯与金属离子的配位并没有阻止晶体相基于环化反应的光致变色性质。  相似文献   

3.
本文合成了三种含异(口恶)唑二芳基乙烯光致变色化合物{1-(3,5-二甲基异(口恶)唑-4-基),2-[2-甲基-5-(2-甲氧基苯基)噻吩-3-基])全氟环戊烯(1o),{1-(3,5-二甲基异(口恶)唑-4-基),2-[2-甲基-5-(3-甲氧基苯基)噻吩-3-基]}全氟环戊烯(2o)和{1-(3,5-二甲基异(口恶)唑-4-基),2-[2-甲基-5-(4-甲氧基苯基)噻吩-3-基]}全氟环戊烯(3o),研究了取代基位置对三种化合物的UV/Vis光谱和荧光性质的影响.实验结果表明,化合物1 3具有良好的光致变色性质和荧光性质;取代基的位置对化合物的性质有显著影响.  相似文献   

4.
为了比较吡啶和噻吩对1-吡啶基/噻吩基-2-芳基乙烯类衍生物固态荧光发射波长Em的影响,以及实现该类化合物Em的精细调节,文章合成了36 种1-吡啶基-2-芳基乙烯衍生物(PyAEY),并对其固态荧光发射波长Em进行测定.将PyAEY的Em与1-噻吩基-2-芳基乙烯衍生物(XAEY)的Em进行比较,观察到:(1)由于吡啶基是缺电子芳基,噻吩基是富电子芳基,在PyAEY和XAEY两者具有相同取代基Y的情况下,PyAEY的固态Em比相应的XAEY减少30 nm以上;(2)通过选择不同的吡啶基(2-Py, 3-Py或4-Py)和Y基团,可以得到波长Em在370~450 nm范围内具有连续发射波长的系列PyAEY化合物;(3)结合PyAEY和XAEY这2类二芳基乙烯化合物,可以得到连续发射波长在370~600 nm范围内的一系列荧光化合物.  相似文献   

5.
在无过渡金属参与情况下,以BH3·Me2S为硼试剂,对一系列(E)-1-芳基-2-三甲基硅基乙烯进行硼氢化反应,用NaOH-H2O2处理反应体系,最终得到有较好收率的1-三甲基硅基-2-芳基乙醇及2-芳基乙醇,其中,2-芳基乙醇是由1-三甲基硅基-2-芳基乙醇在碱性条件下,发生Brook重排反应并脱除硅基的产物.结果表明,在对(E)-1-芳基-2-三甲基硅基乙烯进行硼氢化反应时,硅基表现出很强的导向性,选择性地生成硼基与硅基同碳的产物.  相似文献   

6.
以2-氨基-1-环戊烯-1-二硫代羧酸(ACDA)为结构单元,与芳醛缩合反应合成了14个新型的2-氨基-1-环戊烯-1-二硫代羧酸缩芳醛希夫碱——2-(取代基苯亚甲基胺基)-1-环戊烯二硫代羧酸,对其红外光谱吸收峰随结构、基团的变化而变化进行了研究.结果表明,基团特征吸收峰的位移变化与共轭体系大小、基团的电子效应及基团在分子中的权重有关.  相似文献   

7.
采用多组态CASSCF和MS-CASPT2方法研究了电子效应调控的1,2-二氰基-1,2-二噻吩基乙烯顺-反异构化反应。结果显示:在中性1,2-二氰基-1,2-二噻吩基乙烯的旋转过程中经历的偏离C=C旋转路径、由其他振动模式主导的圆锥交叉S_1/S_0-CI对其旋转速度和旋转单向性有一定的阻碍作用;阳、阴离子的D_0和D_1态在θ=90°处相交,由D_1→D_0的无辐射跃迁无势垒,旋转保持了良好的转速和方向。研究证明了电子效应对光异构化过程的有效调控。  相似文献   

8.
合成了一种含萘并螺噁嗪的光致变色化合物N-乙基-3,3-二甲基-5-甲氧基螺吲哚啉-2,3’-[3H]萘并[2,1-b][1,4]噁嗪。通过^1H NMR,IR和元素分析表征了它的分子结构,利用紫外光谱和荧光光谱初步探索了目标产物的光致变色性能。吸收光谱结果表明,目标分子的氯仿溶液经紫外光照射后,其开环体在587nm处有较强的吸收而呈现蓝色,停止紫外光照射,溶液恢复为无色,显示了良好的光致变色性能;发光光谱结果显示,目标分子经紫外光激发后其开环体在435nm处有较强的蓝光发射。  相似文献   

9.
报道了α 硫羰基硫代甲酰胺与亚磷酸三甲酯的反应。研究结果表明在乙醚溶剂和室温时生成 2 ,2 ,4 ,5 四取代 1,3 二硫杂环戊烯 4的衍生物 ;在二甲苯溶剂和 90 10 0℃反应时主要生成 1,2 二胺基硫代甲酰基 1,2 二芳基乙烯 ;而在二甲苯溶剂中回流反应时则生成 2 ,5 二胺基 3,4 二芳基噻吩衍生物  相似文献   

10.
设计、合成了结构新颖的1,4-二(5'-醛基噻吩基-2')-2,5-二辛氧基苯,并对其结构进行了表征.应用钯催化剂以三丁基锡噻吩与取代的对-二溴苯(3)反应(Stille偶合)生成取代的苯基噻吩(4),产率达到95.2%.由于目标产物(5)本身具有多芳环共轭体系.其荧光效应相当强烈,在氯仿溶液中紫外-可见吸收(UV-vis)和荧光发射(PL)的最大波长分别为413 nm和477 nm,固态荧光发射(PL)波长为504 nm.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

16.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

17.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

18.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

19.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

20.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

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