首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
The dibenzo[3n]crown-n were synthesised from1,2-bis(o-hydroxyphenoxy)ethane obtained from 1,2-bis(o-formylphenoxy)ethane via Bayer-Willigeroxidations with H2O2/CH3COOH in good yields. The cyclic condensation of 1,2-bis(o-hydroxyphenoxy)ethanewith dichlorides, and ditosylates of polyethylene glycols in DMF/Me2CO3 gave the macrocyclesdibenzo[15]crown-5, dibenzo[18]crown-6, dibenzo[21]crown-7 anddibenzo[24]crown-8. The structures were identified using IR, mass, 1H and 13C NMR spectroscopy. Therecognition of the molecules for the cations, Li+, Na+, K+, Rb+ and Zn2+were conducted quantitatively with steady state fluorescencespectroscopy. The 1:1 association constants in acetonitrileshowed a good relation of the appropriate size of the macrocyclic ether towards the fitting cationradii. Namely, dibenzo[15]crown-5 was the best for Li+ binding and more than 100 times better thanNa+ and K+. Dibenzo[21]crown-7 was excellent for Rb+ binding while K+ is 100 timesless preferred. The largest crown ether studied, dibenzo[24]crown-8, exhibited the order of binding power,Rb+ > K+ > Na+. Zn2+ displayed, however, a marked binding with only dibenzo[18]crown-6.p>  相似文献   

2.
4-[3-(1-benzopyran-2-one)] derivativesof benzo[12]crown-4, benzo[15]crown-5 andbenzo-[18]crown-6 were synthesized from4-[3-(1-benzopyran-2-one)]-1,2-dihydroxy-benzenereacting with bis-ethyleneglycol dihalides orpentaethylene glycol ditosylate in alkali carbonate/DMF/water. The original products were identified byhigh resolution EI-mass spectra as well as IR,1H-NMR and 13C-NMR spectroscopy. The 1 : 1binding constants of Mg2+, Li+, Na+ andK+ with the coumarin-benzocrowns were estimated usingfluorescence emission spectroscopy in acetonitrile.The complexing enhanced quenching fluorescence spectra(CEQFS) and complexing enhanced fluorescence spectra(CEFS) exhibited the ion binding powers due tocationic recognition rules of the macrocycles.  相似文献   

3.
以两种不同取代的2-氨基二苯甲酮为原料,氯苯为溶剂,BF3-Et2O为脱水剂,通过分子间脱水一步环化缩合制备非对称二苯并[b,f][1,5]二氮杂环辛四烯衍生物。运用HPLC监控反应过程,优化合成工艺,得到最佳反应条件为:等物质的量的两种不同取代2-氨基二苯甲酮和BF3-Et2O,在氯苯中回流反应12 h。化合物4a^4c为新化合物,其结构经1H NMR,13C NMR和MS(ESI)表征。  相似文献   

4.
Abstract

The 4-H, 4-methyl and 4-phenyl derivatives of benzo-α-pyrone of 12-crown-4 and 15-crown-5 were synthesised starting from 4-substituted-6,7-dihydroxy- and 7,8-dihydroxybenzo-α-pyrones which reacted with dichloropolyethylene glycols in DMF/water/alkali carbonate. The coumarin-macrocycles were identified by elemental analysis, IR, EI-GC-MS as well as 1H, 13C NMR spectroscopy. The full experimental and spectral data is reported along with ion binding data studied in acetonitrile using fluorescence spectroscopy. The binding of the fluorogenic coumarin-crowns with Li+, Na+ and K+ were recognized as specific alterations on their fluorescence spectra that strongly originated from the structures. The observed CEQFS depending on the bound cation radii and macrocycle size evidenced the rules of cationic recognition of macrocycles. Some 15-crown-5 derivatives exhibited interesting Li+ and Na+ binding selectivities.  相似文献   

5.
Yıdız G  Yapar G  Erk C 《Talanta》2004,64(4):865-868
The Na+ association constants, K11 and β12, of 1/1 and 1/2 stoichiometry of macrocycles of (1,2)dibenzo[15]crown-5, (1,3)dibenzo[18]crown-6, (1,4)dibenzo[21]crown-7, (2,3)dibenzo[21]crown-7, (2,4)dibenzo[24]-crown-8 and dicyclohexano[24]crown-8 were determined in THF/water, (50/50), mixtures. We used a Methrom Na+ ISE for the potentiometric measurements and applied the 1/(βnm[Ao+])n+m−1=(1−nPc)(1−mPc)/Pc equation where the Pc=P/[1+(m−1)P] and P is the mole fraction of the complexed cation, [An+Lm] for association constants with linear best fit. Results were in well agreement with the macrocyclic size and cation radii relationships. Measurements showed the role of aromatic groups of macrocyclics in THF/water (50/50) which allowed the macrocyclic molecules more selectively bind Na+ compared to the associations those obtained in water.  相似文献   

6.
4-H, 4-methyl and 4-phenyl-1-benzopyran-2-one derivatives of [18]crown-6 derivatives were synthesised from 6,7- and 7,8-dihydroxy-1-benzopyran-2-one reacting with pentaethylene glycol ditosylate in K2CO3/DMF/water. The products were identified by elemental analysis, EI-GC-mass spectra and 1H-NMR spectroscopy. The Na+ association constants of some coumarin derivatives were determined with an ion selective electrode in water. The Na+ , K+, Ba2+ and Sr2+ binding role of such compounds were particularly observed as remarkable alterations in acetonitrile. The 1 : 1 associations constants of K+ and Na+ with some coumarin-[18]crown-6 derivatives estimated by this way in acetonitrile exhibited the utility of complexing enhanced quenching fluorescence spectra for the ion binding power of the such macrocycles.  相似文献   

7.
程晓红  傅长金   《中国化学》2007,25(11):1762-1765
本文从商品化的间溴苯甲醚和对甲氧基苯甲醛出发,通过傅-克酰基化反应、串联的羟醛缩合及1,4-迈克尔加成反应,得到三芳基取代的1,5-二酮,然后用查尔酮(Chalcone)作氧化剂,二酮与BF3.Et2O 反应形成吡喃鎓盐,再与苯基乙酸钠盐缩合得到芳香二溴代衍生物,产物的DMA溶液在DBU和钯催化剂的作用下,160°C 加热12 h进行脱卤化氢环化反应, 生成四甲氧基取代的二苯并并四苯(DBN)类衍生物。并报道了产物的晶体结构和在溶液中的聚集效应。  相似文献   

8.
以邻氨基二苯甲酮为原料,经自身缩合环化合成了3种二苯并[1,5]二氮杂芳辛四烯衍生物(1a~1c);以邻苯二甲酸酐和溴苯为原料经傅-克反应制得中间体2-(4-溴苯甲酰溴)苯甲酸(M1);M1经叠氮化后自缩合制得6,12-二(4-溴苯基)二苯并[b,f][1,5]二氮杂环辛四烯(1d);以邻氨基苯甲酸甲酯为原料,经自身缩合环化制得中间体二苯并[b,f][1,5]二氮杂环辛四烯-6,12(5H,11H)-二酮(M2);M2经氯化合成6,12-二氯二苯并[b,f][1,5]二氮杂环辛四烯(1e),化合物1a~1e的结构经~1H NMR,~(13)C NMR和ESI-MS表征,其中化合物1c为新化合物。利用超临界色谱(SFC)技术对化合物1a~1e实现了手性拆分,获得5对具有高旋光度的光学活性异构体(ee99%)。  相似文献   

9.
Tuncer H  Erk C 《Talanta》2003,59(2):303-309
The complexing of Eu(fod)3 with macrocyclic ethers, benzo[15]crown-5, benzo[12]crown-4, dibenzo[20]crown-6, dibenzo[23]crown-7 and dibenzo[26]crown-8 was observed on their 1H-NMR spectra and the selective binding constants at 400 MHz and 305 K in CDCl3 were reported. The Eu(fod)3 interaction displayed the selective binding role of oxygen on macrocyclic, H2COCH2, backbones with o- or m-dioxyphenyl groups referring the 1H chemical shifts. The estimated equilibrium constants, Ka of 1:1 ratio of interactions were in accordance with the Eu3+ ionic radii to bind the oxygen sites depending on the macrocyclic size and conformation of the ethers. The minimum lanthanide-macrocyclic ether distance displayed the maximum stability so that benzo[3n]crown-n (n=4, 5) group was found to bind the Eu(fod)3 moderately whilst dibenzo[3n+2]crown-n (n=6-8) oligomer chemical shifts were induced largely since the such Eu3+ complexes are more stable with larger ethyleneoxy groups.  相似文献   

10.
Some novel bis-(substituted-phenoxy) ended glycols were synthesised usinghydroxy aromatics of vanillin, o-vanillin, iso-vanillin and 4-hydroxy coumarin which reacted with bis-dihalides of polyglycols in the presence ofDMSO/alkali carbonate. The novel podands, Ar-(CH2CH2O)m-Ar,(m = 1–4), were identified with IR, 1H-NMR, 13C-NMR and mass spectrometry. The various (formyl-methoxy)phenyl and 4-oxycoumarin derivatives of glycols were studied to estimate the cation binding selectivity of SCN- salts ofLi+, Na+, K+ and Zn2+ cations in acetonitrile using steady statefluorescence spectroscopy. The relevant structures of podands have shown goodselectivity depending on the cation and the glycollength, although the chromophoreend groups have no specific contribution on binding.  相似文献   

11.
Data on the synthesis, reactions, crystal structure, and spectral characteristics of benzo[b]tellurophene, dibenzo[b,d]tellurophene, and their derivatives are reviewed and analyzed.  相似文献   

12.
综述了近四年来新型超分子主体化合物柱芳烃的合成、发展和应用.其中,柱芳烃及其衍生物的合成主要有两种有机化学合成策略,即"先成环后修饰"和"先修饰后成环".由于这类新型主体化合物具有非常特殊的空间结构和理化性质,目前,它主要应用在主客体包合与分子识别、自组装体系的构筑和智能材料等领域.  相似文献   

13.
The 9,10-anthraquinone-[12]crown-4, [15]crown-5 and [18]crown-6 derivatives were synthesized from 1,2-dihydroxy-9,10-anthraquinone and 1,8-dihydroxy-9,10-anthraquinone which were condensed with dihalides or ditosylates of polyethylene glycols in alkali carbonate/DMSO. The 9,10-anthraquinone derived polyoxacyclo-alkanes were characterized with IR, mass spectrometry, 1H, 13C spectroscopy and elemental analysis. The cation binding properties were studied with UV-vis spectroscopy. The association constants found in acetonitrile were selectively dependent on the cation radius and macrocycle size as well as the molecular structures. The observed results from UV-vis studies, however, showed the stronger complexing role of 1,2-derived macrocycles compared to those of 1,8-derivatives. The theoretical conformational analysis and the energy optimisations of the 9,10-anthraquinone-macrocycles carried out with MM+ method explained the binding results.  相似文献   

14.
Calix[4]arenes with substituents at three of the four OH groups of the lower rim have been synthesized to investigate their properties as ionophores for Na+ and K+ metal ions. Crystal structures of these trisubstituted compounds revealed that the calixarene moiety has adopted a partial cone conformation, however the precise shape of the molecule, and intra- and intermolecular interactions, are significantly different due to variations of the substituents. Compound L2 encapsulated an acetonitrile molecule in the cavity of the calix moiety, held by C–H?π interactions. In the case of L3, the 2-(2-chloroethoxy)-ethanol substituent is involved in strong intramolecular C–H?π interactions with the centroid of the phenyl rings of the calix, bringing the 2-(2-chloroethoxy)-ethanol moiety inward the calix cone, which prevented the entry of any solvent molecule into the cavity. The complexation properties of L2L4 with Na+ and K+ ions have been investigated in chloroform–methanol mixture by 1H NMR and an attempt has been made to isolate these complexes in the solid state. Complexation studies reveal that only L3 forms a complex selectively with K+, involving 2-(2-chloroethoxy)-ethanol as a coordinating moiety. The association constant (1.4 × 105 M−1) of the complex has also been determined.  相似文献   

15.
A novel two-step method was developed to prepare individual p-isopropenylcalix[n]arenes [n=4, 6, 8]. In the first step, linear phenolic oligomers were prepared in a basic medium from p-isopropenylphenol and paraformaldehyde. The second step, cyclization of the linear oligomers was carried out at higher temperatures. Ethylene glycol was used as medium, and sodium tetraborate-decahydrate as the catalyst. O-Acetylated derivatives were obtained by acetylation of the phenolic hydroxyl groups of p-isopropenylcalix[n]arenes [n=4, 6, 8]. The p-isopropenyl-calix[n]arenes and their acetylated derivatives were characterized by IR, 1H NMR and UV spectroscopy, and elemental analysis. Their ability to extract metal cations from aqueous solutions was evaluated via metal picrate extraction experiments. A parallel investigation of the cation-binding ability of the p-tert-butylcalix[n]arenes [n=4, 6, 8] and their acetylated derivatives was also performed. The p-isopropenylcalix[6]arene hexaacetate is the most effective extracting agent for metal picrates, and shows strong affinity towards Rb cation.  相似文献   

16.
The synthesis of new difunctionalized 2,6-dioxatricyclo[3.3.1.03,7]nonanes is described. This type of structure is an interesting synthetic building block for potential bioactive molecules and it was prepared from 8-oxabicyclo[3.2.1]oct-6-en-3-one having a NHBoc function on C-1. This precursor was obtained by a [4+3] cycloaddition reaction of 2-tert-butoxycarbonylaminofuran and the oxyallyl cation generated in situ from 2,4-dibromo-3-pentanone. Reduction of the carbonyl group at C-3 was accomplished in high yield and stereoselective manner to afford the corresponding axial alcohol at C-3 as a major product. Further intramolecular haloetherification of this type of alcohols with NBS and I(py)2BF4 led to the corresponding bromo and iodo-derivatives at C-8 of the 2,6-dioxatricyclo[3.3.1.03,7]nonane framework, in high yield. Epoxidation of 8-oxabicyclo[3.2.1]oct-6-en-3-ol followed by treatment with NaCN, NaN3, and/or NaOH in MeOH afforded 8-hydroxy-2,6-dioxatricyclo[3.3.1.03,7]nonanes in high yield via a transannular hydroxycyclization mediated by a base and through an alkoxide intermediate. The new 2,6-dioxatricyclo[3.3.1.03,7]nonanes were tested for biological activity against HIV-1 virus and MT-4 lymphoid cell line, showing a low anti-HIV activity and a high degree of cytotoxicity.  相似文献   

17.
《Analytical letters》2012,45(5):768-775
Nine series of chromogenic mono- (A1-A2) and di- (B1-B7) substituted azocalix[4] arene analogues containing more than one azo group were described. Different chelating agents like ester and ketone moieties were grafted on the lower rim position of azocalix[4]arenes. The selective extraction properties of Fe3+ cation were studied by liquid-liquid extraction. This extraction process was carried out by using compounds A1-A2 and B1-B7. The results proved that coupling of phenylazo groups onto the upper rim of azocalix[4]arenes yielded greater efficiency and selectivity for carrying the Fe3+ cation in the extraction process at pH 2.2.  相似文献   

18.
1,3-Bis[tris(trimethylsilyl)methyl]-2,4,5-trichalcogena-1,3-disilabicyclo[1.1.1]pentanes display unusual short bridgehead Si---Si distances despite the absence of formal Si—Si bonds, and chalcogen---chalcogen interactions are observed by nmr, X-ray analysis and electronic spectroscopy.  相似文献   

19.
设计合成了2个吡啶基菲咯啉衍生物2-(3-吡啶基)咪唑[4,5-f]1,10-菲咯啉(G1)和2-(4-吡啶基)咪唑[4,5-f]1,10-菲咯啉(G2),通过元素分析、质谱和核磁共振氢谱对其结构进行了表征。 利用紫外吸收光谱和荧光光谱法考察了所合成化合物与六元瓜环Q[6]、七元瓜环Q[7]的相互作用,以及体系pH值对主-客体相互作用的影响。 在酸性条件下,Q[6]、Q[7]与Gl以及Q[6]与G2均发生包合形成1∶1的包合物,并有荧光增敏作用;Q[7]与G2作用形成1∶2包合物,且对G2有荧光猝灭作用;Q[6]、Q[7]与G1的包合常数分别为3.00×104和1.86×104 L/mol;Q[6]、Q[7]与G2的包合常数分别为1.64×104和1.01×103 L/mol。 随着体系酸性减弱,瓜环与客体作用减弱,在中性条件下,瓜环未与客体发生包合作用。  相似文献   

20.
新型环烷烯并嘧啶并噻唑-3-酮类化合物的合成   总被引:1,自引:0,他引:1  
胡晓芬  冯亚青  苏琦 《有机化学》2005,25(11):1406-1409
以环戊酮、环庚酮为起始原料合成的环烷烯并[1,2-d]嘧啶-2-硫酮(2)与氯乙酸、芳香醛反应, 合成具有潜在抗癌活性的稠合杂环化合物5-芳基-2,8-二芳亚甲基-2,3,6,7-四氢-5H,8H-环戊烯并[1,2-d]噻唑并[3,2-a]嘧啶-3-酮(3)以及5-芳基-2,10-二芳亚甲基-2,3,6,7,8,9-六氢-5H,10H-环庚烯并[1,2-d]噻唑并[3,2-a]嘧啶-3-酮(4). 34的结构经1H NMR, IR, MS分析确认.  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