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1.
以二苯并噻吩为原料合成了中间体2,8-二溴二苯并噻吩和2,8-二甲酰基二苯并噻吩,并从这两种化合物出发,分别利用Heck反应和Wittig反应合成了具有C2v对称性的一系列二苯并噻吩衍生物。用核磁共振、红外、质谱等光谱手段表征了新化合物的结构,对这些化合物的光物理特性进行了评价。结果表明:2,8-二[2-(吡啶-4-基)乙烯基]二苯并噻吩(I)的紫外吸收峰随着溶剂极性的增加而出现蓝移现象,而其他化合物的紫外吸收峰随溶剂极性增加往长波方向移动;化合物I具有较低的荧光量子效率;用750~920nm的飞秒激光激发时化合物I的溶液表现出明显的双光子吸收特性。  相似文献   

2.
萃取精馏分离苯和环己烷的二元混合溶剂   总被引:3,自引:0,他引:3  
混合溶剂萃取精馏技术是一种极具发展潜力的新型分离技术.通过一个简单实用的气液平衡实验装置考察了多个萃取精馏分离苯/环己烷近沸点体系的二元混合溶剂:二甲基亚砜和N,N-二甲基甲酰胺、二甲基亚砜和N-甲基吡咯烷酮以及N-甲基吡咯烷酮和N,N-二甲基甲酰胺的性能.结果发现,混合溶刑分离效果比简单溶剂更好,且混合溶剂存在最佳组成;当混合溶剂的摩尔比接近1时,其性能最佳;N,N-二甲基亚砜和N,N-二甲基甲酰胺组成的混合溶剂是所有被考察萃取刑中最好的混合溶剂;另外还发现了优于文献报道的简单溶剂N。N-二甲基甲酰胺.  相似文献   

3.
本文以卤代三苯胺、5-醛基-2-噻吩硼酸为原料,[1,1-双(二苯基磷)二茂铁]二氯化钯为催化剂,通过Suzuki偶联反应,制备了D-(D'-A)n(n=1~3)型醛基化合物L1、L2、L3,其中D为供电子(Donor)三苯胺、D'为协同供电子噻吩、A为吸电子(Acceptor)醛基,其结构经1H NMR,13C NMR,MALDI-TOF MS,IR表征,利用紫外-可见分光光度仪、荧光光谱仪,初步研究了它们的光学性质及构效关系。结果表明,L1、L2、L3随着溶剂极性的增加,最大吸收波长变化不大,最大发射波长发生红移,发射强度降低。在THF溶剂中,它们都有两个吸收峰(L1:297 nm,398 nm;L2:290 nm,417 nm;L3:293nm,414 nm),而最大发射波长基本都在510 nm处,荧光强度相差不大。  相似文献   

4.
报导了在乙醇-水体系中,分别用11-硅钨酸、12-硅钨酸与3,6-二(二甲氨基)-二苯并碘六环反应,制得一系列未见文献报导的大阳离子杂多酸盐。它们溶于N,N-二甲基甲酰胺、N,N-二甲基乙酰胺和二甲基亚矾等溶剂,但不溶于水、乙醇、甲醇、丙酮、氯仿和苯。还报导了它们的红外、紫外、热重分析,~1H-NMR及电导等性质。  相似文献   

5.
以苯并咪唑与2,6-二溴吡啶为原料,经过Ullmann反应合成了2,6-双(1-苯并咪唑基)吡啶.目标化合物经IR、1 H NMR、13C NMR和元素分析表征.对所合成目标化合物的紫外及荧光光谱进行了研究,它们的最大紫外吸收峰及荧光发射峰随着溶剂极性的增大而发生了红移.  相似文献   

6.
以苯并咪唑与2,6-二溴吡啶为原料,经过Ullmann反应合成了2,6-双(1-苯并咪唑基)吡啶.目标化合物经IR、1 H NMR、13 C NMR和元素分析表征.对所合成目标化合物的紫外及荧光光谱进行了研究,它们的最大紫外吸收峰及荧光发射峰随着溶剂极性的增大而发生了红移.  相似文献   

7.
以4,6-二(叔丁基二甲基甲硅烷基氨基)(TBS)-1,3-二(叔丁基二甲基甲硅烷氧基)苯(DAR)与4,4′-二酰氯三苯胺缩聚制得前聚体(TPA-PrePBO),并通过热关环,首次制备出具有高相对分子质量的D-A型光电材料聚(三苯胺基苯并二噁唑)共聚物(TPA-PBO)。前聚体TPAPrePBO在常规的有机溶剂如N-甲基吡咯烷酮(NMP)、N,N-二甲基乙酰胺(DMAc)和二甲基亚砜(DMSO)中具有优异的溶解性能。TPA-PBO的紫外可见吸收光谱的最大吸收峰位于486nm处,荧光光谱的最大激发峰位于553nm处,能带间隙仅有2.20eV,远小于相似结构的三苯胺-聚酰亚胺(TPA-PI)和聚对苯撑苯并二噁唑(PBO)。同时发现TPA-PBO聚合物具有较高的热稳定性,在氮气气氛中的起始分解温度达到527℃。研究结果表明TPA-PBO有望作为一种易加工、高稳定性、低激发电压的新型有机光电材料。  相似文献   

8.
合成了一种基于杂环体系噻吩的新化合物2,5-二(对-N,N-二甲氨基苯乙烯基)噻吩,测定结果表明其能发射出强的蓝绿色荧光,发射蜂位于530nm左右,荧光寿命约为1ns。在不同极性溶剂中,化合物的荧光光谱表现出显著的溶剂效应。800nm fs激光的激发下,目标化合物发出很强的频率上转换荧光,双光子激发荧光谱在外形上与单光子激发荧光谱非常相似。用荧光法测定了目标化合物的双光子吸收截面,结果表明该化合物具有大的双光子吸收截面。  相似文献   

9.
以4-溴-1,8-萘二甲酸酐为起始原料通过Sonogashira偶联反应合成了一种新型萘酰亚胺衍生物(N-吗啉乙基)-4-(4-羟基苯乙炔基)-1,8-萘酰亚胺(A),其结构通过~1H NMR、~(13)C NMR、HR-MS(ESI)表征,并对化合物A在6种不同极性有机溶剂和甲醇/四氢呋喃混合溶剂中的荧光发射光谱,以及A在四氢呋喃中的双光子诱导荧光光谱进行了分析.结果表明:A具有溶质变色效应,随溶剂极性的增大,A的荧光发射峰发生红移,且荧光强度下降.并且A在波长820 nm处的有效双光子吸收截面为90 GM.此外,A可成功定位于溶酶体,与溶酶体商品化染料Lyso Tracker Red的共定位系数高达0.902 6.因此,化合物A作为一个新型的双光子吸收材料,可作为双光子溶酶体示踪剂用于细胞成像.  相似文献   

10.
合成了两种基于吡啶/芴的有机配体9-(2-氯-3-吡啶基)-9-羟基芴(2-ClPyFOH)和9-(6-溴2-吡啶基)-9-羟基芴(6-BrPyFOH).通过质谱和核磁对这些化合物的结构进行了详细表征.9-(2-吡啶基)-9-羟基芴(PyFOH)、6-BrPyFOH和2-ClPyFOH在环己烷、二氯甲烷、乙酸乙酯、乙醇和乙腈溶液中的最大吸收峰分别是268/275/275、275/275/275、268/274/271、268/274/271和268/275/271nm.结果表明:除乙酸乙酯外,这些化合物的吸收光谱在同一溶剂中随着吡啶上卤素取代基的吸电子能力增强光谱红移.在这5种溶剂中,3种化合物的发射光谱的发射峰分别为313/356/356、327/358/365、359/367/312、316/316/401和386/377/438nm.PyFOH和6-BrPyFOH的发射光谱同在其他极性较低的溶剂中相比,在乙醇溶剂中发生蓝移,这可能是由吡啶基团上n-π*电子转移态的溶剂效应所引起的.2-ClPyFOH的发射光谱除乙酸乙酯外,随着溶剂极性的增加光谱发生红移.在吡啶2-位和6-位的氯原子和溴原子将赋予这些配体具有不同的结构从而具有不同的功能和光学性质.  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.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
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   

16.
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   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
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   

19.
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   

20.
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   

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