首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 124 毫秒
1.
香豆素类衍生物是一类具有抗病毒等许多生理活性的化合物[1-3],其合成和性质的研究一直受到关注[4].  相似文献   

2.
合成容易脱水的对甲苯磺酸镉,首次用于有机溶剂中的电化学研究.Cd( )在Cd(p-CH3C6H4SO3)2+TBAP+DMSO中Pt电极上还原时,首先出现镉的欠电位沉积,然后电沉积镉.4-甲基-7-羟基香豆素、3-氨基香豆素与镉离子配位,使镉离子的还原电位向负方移动.  相似文献   

3.
香豆素在离子液体(BMIMBF4)中的电还原行   总被引:2,自引:2,他引:0  
室温离子液体由大的有机阳离子(咪唑、吡啶、季铵和季等)和各种各样的阴离子[AlCl-4, PF-6, BF-4, CF3SO-3, (CF3SO3)2N-等]组成, 是一种新型的溶剂, 具有稳定性好、蒸气压小、毒性小和不易燃等优异的物理化学性质, 已引起了人们的广泛关注. 因而在这种新型溶剂中进行有机物电化学行为的研究, 用于评价其作为“绿色”电化学或新型电化学反应的可行性很有必要.  相似文献   

4.
合成了四种齐聚噻吩衍生物:5,5"-二氰基-2,2’:5’,2"-三噻吩 (DCN3T), 5,5"’-二氰基-2,2’:5’,2":5",2"’-四噻吩 (DCN4T), 5,5"’-甲氧基-2,2’:5’,2":5",2"’-四噻吩(DMO4T) 和 4,4"-二羧基-5,5"-二丙基-2,2’:5’,2"-三噻吩 (BP3T-DCOOH),研究了它们的电致变色性质,研究结果发现,这四种齐聚噻吩衍生物膜在电场作用下,可以发生可逆的颜色变化。  相似文献   

5.
用MSCV法研究了烯丙醇在多孔Pt电极上0.5ol.dm^-3HCLO4中的电还原。烯丙醇电还原时主要涉及二类反应:烯丙基上C-OH断键生成丙烯; 丙烯进一步氢化生成丙烷。表征丙烯及丙烷的诸碎片M/Z的质谱电流(IM)-电极电位(Φ)扫描曲线线详细描绘了各分步反应的状况。在一定电位范围, 各M/Z的lgIM-Φ呈线性; 求得各有关M/Z的Tafel斜率。根据实验结果对反应机理进行了详细分析。  相似文献   

6.
陈剑  刘佩芳  王辉  查全性 《化学学报》1993,51(2):150-154
用MSCV法研究了烯丙醇在多孔Pt电极上0.5ol.dm^-3HCLO4中的电还原。烯丙醇电还原时主要涉及二类反应:烯丙基上C-OH断键生成丙烯; 丙烯进一步氢化生成丙烷。表征丙烯及丙烷的诸碎片M/Z的质谱电流(IM)-电极电位(Φ)扫描曲线线详细描绘了各分步反应的状况。在一定电位范围, 各M/Z的lgIM-Φ呈线性; 求得各有关M/Z的Tafel斜率。根据实验结果对反应机理进行了详细分析。  相似文献   

7.
刘平  王永光  潘万章  黄明生  邓文基  童真 《中国化学》2006,24(10):1305-1308
The photophysical and electrochemical properties of a family of oligothiophene derivatives in solution werestudied.It was found that the cyano and the vinyl group could increase fluorescence yield in solution,while theformyl and carboxyl group could decrease energy gap.With increasing the chain length of thiophene ring,the oxi-dation potential could be decreased.  相似文献   

8.
炔丙醇在多孔Pt黑电极上, 0.5mol.dm^-3HCLO4溶液中电还原的MSCV研究结果表明炔丙醇电还原时既涉及烯丙基C-OH断键反应亦涉及炔丙基上C-OH断键反应生成烃类。此外有少量炔丙醇直接质子化生成部分饱和的烯丙醇。表征各种反应产物的M/Z的质谱电流-电极电位扫描曲线(IM-Φ)详细描绘了各分步反应的图象。各M/Z的1gIM-Φ曲线在一空电位范围内呈线性, 并求得它们的Tafel斜率。依据实验结果对反应机理进行了详细分析。  相似文献   

9.
刘佩芳  陈剑  王辉  查全性 《化学学报》1993,51(2):155-160
炔丙醇在多孔Pt黑电极上, 0.5mol.dm^-3HCLO4溶液中电还原的MSCV研究结果表明炔丙醇电还原时既涉及烯丙基C-OH断键反应亦涉及炔丙基上C-OH断键反应生成烃类。此外有少量炔丙醇直接质子化生成部分饱和的烯丙醇。表征各种反应产物的M/Z的质谱电流-电极电位扫描曲线(IM-Φ)详细描绘了各分步反应的图象。各M/Z的1gIM-Φ曲线在一空电位范围内呈线性, 并求得它们的Tafel斜率。依据实验结果对反应机理进行了详细分析。  相似文献   

10.
利用循环伏安法研究了烷氧基聚紫精的电氧化还原性能,测定了它们的两步还原电位、峰电流和表现扩散系统(D),结果表明:D随着PAoV结构中所含醚键的增加而减小;并对第一步还原反应的可逆性进行了研究,发现第一步还原反应的可逆性优于第二步还原反应,同时证明电极反应是由扩散步骤控制的;PAoV具有良好的抗电疲劳性能;并研究了体系pH值和扫描范围对PAoV的电氧化还原性能的影响。  相似文献   

11.
详细考察了各种基质、重原子微扰剂和实验条件的影响之后,成功地实现了多种香豆素衍生物的室温磷光(RTP)发射。在滤纸基质上,以1mol/L的Pb(Ac)_2作重原子微扰剂时,近20种香豆素衍生物大都能产生较强的RTP发射。而且某些衍生物的RTP强度和λ_(ex)/λ_(em)等特性间呈现出明显的取代基效应。本文还对这些衍生物在滤纸基质上的室温荧光(RTF)和其混和光谱(在重原子微扰剂存在下以荧光方式测得的光谱)等特性作了对比测定,发现其间亦呈现类似的取代基效应。有关香豆素衍生物的RTP特性,迄今尚未报道。这类衍生物RTP发射的实现,预示着它们用作RTP标记物的可能性。  相似文献   

12.
Five new coumarin amide derivatives were synthesized with coupling reagent,the structures of which were characterized by IR,1H NMR,13C NMR,MS and element analysis.Their spectral properties were studied in dichloromethane,in N,N-dimethylformamide(DMF) and in solid state.Solvent polarity has less influence on the UV-Vis maximum absorption at about 430 nm.The maximum emission wavelengths change from 464 nm to 474 nm in dichloromethane,from 476 nm to 482 nm in DMF and from 521 nm to 548 nm in solid state,respec...  相似文献   

13.
本文合成了三个噻吩桥联香豆素衍生物,7-N,N-二乙氨基-3-(5-(芘-1-基)噻吩-2-基)-香豆素(Py-Th-NC),7-(N,N-二乙氨基)-3-(4-(5-(7-(N,N-二乙氨基)-香豆素-3-基)噻吩-2-基)苯基)-香豆素(NCTh-Ph-NC)和3-(4-(5-(7-(N,N-二乙氨基)-香豆素-3-基)噻吩-2-基)苯基)-香豆素(NC-Th-Ph-C),分别采用HRMS、1H NMR和IR对其结构进行了表征,并研究了三个化合物的发光性能、电化学性能及热稳定性。结果表明,这些香豆素衍生物具备很好的热稳定性,并在二氯甲烷溶液中显示蓝绿色或绿色荧光。  相似文献   

14.
香豆素衍生物的荧光发射能计算及XC泛函的合理选择   总被引:2,自引:0,他引:2  
王溢磊  吴国是 《物理化学学报》2007,23(12):1831-1838
采用含时密度泛函理论(TDDFT)与单激发组态相互作用(CIS)处理相结合的计算方案对香豆素系列15种已知荧光化合物的发射能进行了系统考察. 结果表明, 发射能与吸收能一样, 其计算值主要取决于交换-相关(XC)泛函的选择. 只要泛函选用得当, 在使用较小基组的TDDFT/6-31G(d)//CIS/3-21G(d)理论水平上即可使绝大部分化合物的实验发射能在精度达0.16 eV以内得以重现. 与吸收能计算不同的是, 无法选用单一的一种泛函来对全系列化合物的发射能作出满意的理论预测. 激发态无明显电荷转移的、7位上有氨(或胺)基取代或有氮原子相连的化合物, 其适用泛函为不含Hartree-Fock(HF)交换能的纯泛函OLYP和BLYP. 而激发态发生较大程度电荷转移的、3 位上有共轭取代基的衍生物, 其适用泛函则为含20%的HF交换成分的混合泛函B3LYP. 因此, 发射能计算中的XC泛函选择, 应同时考虑取代基团效应以及激发态的电子结构特征. 其中, 发射能计算值受XC泛函中HF交换能比例的影响十分敏感. 文中还对激发能计算中的溶剂效应校正方案和激发态几何优化精度的影响进行了讨论.  相似文献   

15.
Yilei Wang  Guoshi Wu   《Acta Physico》2007,23(12):1831-1838
A scheme of time-dependent density functional theory (TDDFT) combined with single-excitation configuration interaction (CIS) approach was employed to make a detailed investigation of the emitting energy for fifteen well-known coumarin derivatives. The results showed that the predicted emitting energies as well as the absorption ones were dominated mainly by the exchange-correlation (XC) functional to be used. So long as a functional is properly chosen, the experimental emitting energy of most derivatives can be accurately reproduced within 0.16 eV by a calculation at the TDDFT/6-31G(d)//CIS/3-21G(d) theoretical level. It was found that, nevertheless, the hybrid functional, B3LYP, well predicted the absorption energies for all the fifteen coumarin derivatives but none of the functionals could work equally well for the emitting energy calculations. Two pure functionals, OLYP and BLYP, yield good emitting energies for the 7-aminocoumarins or derivatives with a N atom connected to 7-position, which exhibit inconspicuous charge transfer (CT) in their excited states, whereas the B3LYP hybrid functional, with 20% Hartree-Fock (HF) exchange energy, performs significantly better than OLYP and BLYP for those 3-substituted coumarins with larger CT in excited states. Thus, in comparison with the absorption energies, the selection of proper functionals for the emitting energy calculations becomes more complex. In all probability, it is effective and doable to choose an XC-functional with alterable fraction of HF exchange energy according to the composition and structure characteristics of molecule.  相似文献   

16.
The methyl coumarins reacted with N‐bromo‐succinimide gave compounds ( a~c ) which on further reacted with various peracetyl sulfhydryl glycose ( 1~3 ) afforded a series of novel coumarin thioglycopyranoside compounds ( 1a~1c, 2a~2c, 3a~3c ). And when used ultrasonic irradiation, this method offered several advantages such as good yields and short reaction time than the silent reaction. All the new compounds were characterized on the basis of the IR, 1H NMR, 13C NMR and elemental analysis.  相似文献   

17.
香豆素衍生物溶液的光谱和光物理行为   总被引:4,自引:0,他引:4  
戴赵华  吴世康 《物理化学学报》1999,15(12):1076-1081
通过对一系列不同取代的香豆素化合物在不同溶剂中的光谱测定,研究了结构和溶剂极性对它们光物理行为的影响.发现了它们的光物理特征与其结构和多种溶剂极性参数间存在的一些关系,为进一步更好的利用这类化合物提供了重要依据.  相似文献   

18.
Rajesh H. Vekariya 《合成通讯》2014,44(19):2756-2788
The synthesis of coumarins through Knoevenagel condensation is one of the most important processes in synthetic organic chemistry and medicinal chemistry. Compounds including a coumarin (2-oxo-2H-1-benzopyran) backbone have a wide range of application in the pharmaceutical field. Thus, many methodologies have been developed for the synthesis of this important class of compounds. However, some methods are always associated with toxic and corrosive catalysts, longer reaction time, poor yield, less purity, and by-products along with the desired product. Furthermore, some of these processes are not efficient and environmentally friendly. Therefore, mild, efficient, and environmentally friendly protocols have been developed recently by many scientists for the synthesis of coumarin derivatives via Knoevenagel condensation with good yield and purity. In this review, we have summarized various methods for the synthesis of coumarins via Knoevenagel condensation.  相似文献   

19.
合成了11个香豆素衍生物,产率53%—79%,利用元素分析、MS和1HNMR对其结构进行了表征.同时,由2-氨基苯并噻唑(ABT)和8-甲氧基香豆素-3-甲酸乙酯(MCC)合成了给体-受体加合物ABT-MCC,通过X射线单晶衍射法测定了其晶体结构,晶体属三斜晶系,P1空间群,晶胞参数为:a=9.5978(19)Å,b=10.686(2)Å,c=10.693(2)Å,α=71.30(3)°,β=70.43(3)°,γ=88.99(3)°,V=973.9(3)Å3,Z=2,Dx=1.359 mg/m3,μ=0.200 mm-1,F(000)=416,R=0.0463,wR=0.0992.结果表明,在ABT-MCC晶体中,分子间通过N—H…N和N—H…O氢键作用形成对称的A…D…D′…A′氢键四聚体,并通过弱的C—H…O氢键连接成为一维超分子链状结构,进而分子间通过π-π堆积作用形成层状结构.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号