Journal of The Chemical Society-perkin Transactions 1最新文献_第9页

Pyrido[1,2-a]quinoxalines: synthesis, crystal structure determination and pH-dependent fluorescence 吡啶醌[1,2-a]:合成、晶体结构测定和ph依赖性荧光

Journal of The Chemical Society-perkin Transactions 1 Pub Date : 2002-12-17 DOI: 10.1039/B102755G

K. Duffy, R. Haltiwanger, A. Freyer, F. Li, J. Luengo, Hung‐Yuan Cheng

引用次数: 5

Synthesis, structure and optical characterisation of silicon phthalocyanine bis-esters 酞菁硅双酯的合成、结构及光学性质

Journal of The Chemical Society-perkin Transactions 1 Pub Date : 2002-12-17 DOI: 10.1039/B108778A

C. Farren, S. FitzGerald, M. Bryce, A. Beeby, A. Batsanov

引用次数: 11

4-Phenyloxazolidin-2-ones and isoindolin-1-ones; chiral auxiliaries for Diels-Alder reactions of N-substituted 1,3-dienes. 4-苯氧恶唑烷-2- 1和异吲哚-1- 1;n -取代1,3-二烯Diels-Alder反应的手性助剂。

Journal of The Chemical Society-perkin Transactions 1 Pub Date : 2002-12-17 DOI: 10.1039/B108059H

Helena McAlonan, James P. Murphy, M. Nieuwenhuyzen, K. Reynolds, P. K. Sarma, P. Stevenson, N. Thompson

引用次数: 28

Tropylium cation capsule of hydrogen-bonded tetraurea calix 4 arene dimers 氢键四脲杯芳烃二聚体的Tropylium阳离子胶囊

Journal of The Chemical Society-perkin Transactions 1 Pub Date : 2002-12-17 DOI: 10.1039/B108043A

L. Frish, M. Vysotsky, S. E. Matthews, V. Böhmer, Y. Cohen

{"title":"Tropylium cation capsule of hydrogen-bonded tetraurea calix 4 arene dimers","authors":"L. Frish, M. Vysotsky, S. E. Matthews, V. Böhmer, Y. Cohen","doi":"10.1039/B108043A","DOIUrl":"https://doi.org/10.1039/B108043A","url":null,"abstract":"The interaction between tropylium salts and tetraurea calix[4]arene derivatives (such as 1 and 2) was studied in solution using 1D, 2D, diffusion, VT NMR and UV–visible spectroscopy. It was found that tropylium salts form charge transfer complexes with both the monomers and dimers of the tetraurea calix[4]arene derivatives depending on the experimental conditions. Compound 1 increases dramatically the solubility of tropylium salts in apolar solvents such as C2D4Cl2, CDCl3 and CD2Cl2 by forming the molecular capsule 1·C7H7+·1. In contrast to the benzene capsule of 1, in 1·C7H7+·1 the hydrogen bonds in the equatorial region that hold together the two parts of the dimer change their directionality faster than the NMR time scale (at 400 MHz) at temperatures higher than 298 K. Interestingly, the free energy barrier for this dynamic process at 298 K (ΔG‡298), depends on the nature of the counter-anion. Free energies of activation of 14.3 ± 0.2 kcal mol−1 and 12.6 ± 0.2 kcal mol−1 were found by total lineshape analysis for the dimeric capsules of C7H7+PF6− and C7H7+BF4−, respectively. The affinity of the tropylium cation toward the dimer's cavity is much higher than that of neutral organic guests. Although exact quantitative values are not available due to the low solubility of tropylium salts in apolar solvents, \u0000a rough estimation in CD2Cl2 shows that the tropylium cation affinity is several orders of magnitude higher than that of benzene, which is known to be a good guest. These results show that once the steric requirements are met, electronic effects may serve as an additional driving force for the formation of such molecular capsules demonstrating the importance of cation–π interactions in such systems.","PeriodicalId":17267,"journal":{"name":"Journal of The Chemical Society-perkin Transactions 1","volume":"6 1","pages":"88-93"},"PeriodicalIF":0.0,"publicationDate":"2002-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75408625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Quantitative characterisation of the hydrogen bonding behaviour on the acceptor functions in oligopeptide derivatives with a fluorinated alcohol 含氟醇寡肽衍生物受体功能上氢键行为的定量表征

Journal of The Chemical Society-perkin Transactions 1 Pub Date : 2002-12-17 DOI: 10.1039/B008747P

M. Plass, I. Schaller

{"title":"Quantitative characterisation of the hydrogen bonding behaviour on the acceptor functions in oligopeptide derivatives with a fluorinated alcohol","authors":"M. Plass, I. Schaller","doi":"10.1039/B008747P","DOIUrl":"https://doi.org/10.1039/B008747P","url":null,"abstract":"The equilibrium constants for the association of a fluorinated alcohol, 1,1,1,3,3,3-hexafluoropropanol with amino acid and peptide derivatives dissolved in methylene chloride were calculated. The mathematical approach for the determination of the equilibrium constant KOH is based on the decrease of the integral intensity of the OH stretching signal in the infrared spectrum. Alternatively, the decrease of the intensities of the acceptor signals can be used for the calculation of individual equilibrium constants KZ, KPeptide and KEster, for the association of the alcohol on the urethane, peptide and ester function, respectively. The equilibrium constants obtained with both approaches for a number of amino acid, di- and tripeptide derivatives will be discussed. Generally, in no case was the ester function involved in a complex formation with the fluorinated alcohol. For most examples the association \u0000constant for the peptide function was larger than for the urethane group. The investigation of the effect of the variation of the concentration on the equilibrium constant shows that up to a ratio cA0/cB0 of the initial concentrations of the alcohol, cA0, and the acceptor compound, cB0, equal to 10, no formation of 1 ∶ 2 or 1 ∶ 3 associates need to be considered.","PeriodicalId":17267,"journal":{"name":"Journal of The Chemical Society-perkin Transactions 1","volume":"102 1","pages":"186-191"},"PeriodicalIF":0.0,"publicationDate":"2002-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75436204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Novel sodium-selective fluorescent PET and optically based chemosensors: towards Na+ determination in serum 新型钠选择性荧光PET和光学化学传感器:用于血清中Na+的测定

Journal of The Chemical Society-perkin Transactions 1 Pub Date : 2002-12-17 DOI: 10.1039/B106474F

T. Gunnlaugsson, M. Nieuwenhuyzen, L. Richard, V. Thoss

{"title":"Novel sodium-selective fluorescent PET and optically based chemosensors: towards Na+ determination in serum","authors":"T. Gunnlaugsson, M. Nieuwenhuyzen, L. Richard, V. Thoss","doi":"10.1039/B106474F","DOIUrl":"https://doi.org/10.1039/B106474F","url":null,"abstract":"The anthracene based fluorescent PET chemosensor 1 and the azo-dye based chemosensor 2 show high selectivity for Na+ over other alkali and alkaline-earth metal cations in the 12–300 mM concentration range in 50 ∶ 50 MeOH–H2O at pH 7.4. Chemosensor 1 shows fluorescence ‘off-on’ switching upon Na+ complexation with λFmax of 440 nm and a log βNa of 2.5 (±0.05) and a pKa of 5.3 with no concomitant changes in the absorption spectra. Conversely, 2 displays only a weak fluorescent emission at around 520–640 nm, and large changes in its absorption spectra upon addition of Na+, with a log βNa of 1.25 (±0.05) and a pKa \u0000of 3.9. In 100% water the sensitivity of 2 for Na+ was somewhat lower with a log βNa of 0.8 (±0.05). The crystal structure of 2, and its corresponding protonated form (2·H+) were obtained, showing 2 in its trans conformation with the crown ether moiety at a 75° angle to the plane of the chromophore. These results, in conjunction with 1H NMR measurements of 2, and UV–VIS measurements of the ion receptor 3, suggest that upon complexation of Na+, the 2′-methoxy group of the crown receptor participates in the Na+ complexation through chelation to the Na+ ion. We propose that this interaction \u0000forces the amine moiety of the crown ether to twist out of the plane of the chromophore, inducing loss of conjugation which gives rise to large Na+-induced spectral changes in the absorption spectra, which are most noticeable for 2.","PeriodicalId":17267,"journal":{"name":"Journal of The Chemical Society-perkin Transactions 1","volume":"275 1","pages":"141-150"},"PeriodicalIF":0.0,"publicationDate":"2002-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76394061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 23

Controlled stepwise conversion of 2,4,6,8-tetrachloropyrimido[5,4-d]pyrimidine into 2,4,6,8-tetrasubstituted pyrimido[5,4-d]pyrimidines 控制2,4,6,8-四氯嘧啶[5,4-d]嘧啶逐步转化为2,4,6,8-四取代嘧啶[5,4-d]嘧啶

Journal of The Chemical Society-perkin Transactions 1 Pub Date : 2002-12-17 DOI: 10.1039/B102224P

Julian S. Northen, F. Boyle, W. Clegg, N. Curtin, Andrew J. Edwards, R. Griffin, B. Golding

{"title":"Controlled stepwise conversion of 2,4,6,8-tetrachloropyrimido[5,4-d]pyrimidine into 2,4,6,8-tetrasubstituted pyrimido[5,4-d]pyrimidines","authors":"Julian S. Northen, F. Boyle, W. Clegg, N. Curtin, Andrew J. Edwards, R. Griffin, B. Golding","doi":"10.1039/B102224P","DOIUrl":"https://doi.org/10.1039/B102224P","url":null,"abstract":"For the rational synthesis of 2,4,6,8-tetrasubstituted pyrimido[5,4-d]pyrimidines, required as purine mimetics, sequential nucleophilic substitutions of 2,4,6,8-tetrachloropyrimido[5,4-d]pyrimidine have been investigated. Reaction conditions have been devised leading to 2,4,6,8-tetrasubstituted pyrimido[5,4-d]pyrimidines with patterns of substitution denoted as abab (reaction with nucleophile 1 at C-4 and C-8, followed by nucleophile 2 at C-2 and C-6) or abac (reaction with nucleophile 1 at C-4 and C-8, nucleophile 2 at C-2 and nucleophile 3 at C-6) or abcd (reaction with nucleophile 1 at C-4, nucleophile 2 at C-8, nucleophile 3 at C-2 and nucleophile 4 at C-6). The use of low temperature, relatively dilute solution and careful addition of the amine nucleophile can control the critical first step. The third step in the production of the abcd pattern leads to two regioisomers, which have been structurally characterised \u0000by 1H NMR and a crystal structure analysis. Selected 2,4,6,8-tetrasubstituted pyrimido[5,4-d]pyrimidines were tested as inhibitors of the cyclin-dependent kinase 1 complex (cyclin B/CDK1), but none of the compounds showed significant activity.","PeriodicalId":17267,"journal":{"name":"Journal of The Chemical Society-perkin Transactions 1","volume":"1 1","pages":"108-115"},"PeriodicalIF":0.0,"publicationDate":"2002-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77797168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

NMR studies on the axial chirality of ortho-substituted push–pull phenyl butadienes 邻取代推拉型苯基丁二烯轴向手性的核磁共振研究

Journal of The Chemical Society-perkin Transactions 1 Pub Date : 2002-12-17 DOI: 10.1039/B107402B

M. Michalik, T. Freier, H. Reinke, K. Peseke

引用次数: 0

Cyclic thiatetraynes: syntheses and structural properties 环己烷:合成及结构性质

Journal of The Chemical Society-perkin Transactions 1 Pub Date : 2002-12-17 DOI: 10.1039/B108403H

Bernhard J. Rausch, D. Werz, S. Rittinger, R. Gleiter, T. Oeser, F. Rominger

引用次数: 1

Formation of inclusion complexes between dimers of (R)-3-hydroxybutanoic acid and β-cyclodextrin: thermodynamic study of the complexation and conformational analysis of the complexed dimers (R)-3-羟基丁酸二聚体与β-环糊精包合物的形成:络合的热力学研究及络合二聚体的构象分析

Journal of The Chemical Society-perkin Transactions 1 Pub Date : 2002-12-17 DOI: 10.1039/B104984B

Jun Li, K. Toh

引用次数: 4