Journal of the Chemical Society, Faraday Transactions最新文献_第10页

Time-resolved resonance Raman spectroscopy of the carbonate radical 碳酸盐自由基的时间分辨共振拉曼光谱

Journal of the Chemical Society, Faraday Transactions Pub Date : 1998-01-01 DOI: 10.1039/A801239C

R. Bisby, Steven A. Johnson, A. Parker, S. Tavender

引用次数: 29

Thermodynamics of the interaction of some chloro- and fluoro-substituted alcohols with bovine α-lactalbumin 某些氯代和氟代醇与牛α-乳清蛋白相互作用的热力学

Journal of the Chemical Society, Faraday Transactions Pub Date : 1998-01-01 DOI: 10.1039/A708066B

N. Kishore, B. Sabulal

{"title":"Thermodynamics of the interaction of some chloro- and fluoro-substituted alcohols with bovine α-lactalbumin","authors":"N. Kishore, B. Sabulal","doi":"10.1039/A708066B","DOIUrl":"https://doi.org/10.1039/A708066B","url":null,"abstract":"The temperature dependence of the excess heat capacity and evaluation of thermodynamic parameters of bovine α-lactalbumin has been studied by high-sensitivity micro differential scanning calorimetry in the presence of 4-chlorobutan-1-ol, n-butanol, 3-chloropropan-1-ol, 3-chloropropan-1,2-diol, propan-1,2-diol, n-propanol, 2,2,2-trifluoroethanol, and ethanol at neutral pH. The chlorosubstituted alcohols are observed to be more effective destabilisers of α-lactalbumin compared with their normal alcohols in the order: 4-chlorobutan-1-ol > n-butanol > 3-chloropropan-1-ol > n-propanol > 2,2,2-trifluoroethanol > 3-chloropropan-1,2-diol > ethanol > propan-1,2-diol. A reversible two-state approximation for the unfolding of the protein has been shown in the absence and presence of these alcohols. A second, smaller, endothermic transition, 23°C beyond the main endotherm was observed only in the presence of 0.125 to 0.250 mol dm-3 3-chloropropan-1-ol. Concentrations higher than 25 mmol dm-3 4-chlorobutan-1-ol resulted in total loss of an observable endotherm. Thermal destabilisation of the protein in these solvent systems is explained on the basis of competing patterns of interactions of the cosolutes with the native versus unfolded states of the protein during the nativedenatured reaction. These results are supported by intrinsic fluorescence, energy transfer and UV difference measurements.","PeriodicalId":17286,"journal":{"name":"Journal of the Chemical Society, Faraday Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87593238","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: 10

Scanning electrochemical microscopy Kinetics of chemical reactions following electron-transfer measured with the substrate-generation–tip-collection mode 扫描电化学显微镜下电子转移后的化学反应动力学用底物生成-尖端收集模式测量

Journal of the Chemical Society, Faraday Transactions Pub Date : 1998-01-01 DOI: 10.1039/A707984B

Rachel D. Martin, P. Unwin

{"title":"Scanning electrochemical microscopy Kinetics of chemical reactions following electron-transfer measured with the substrate-generation–tip-collection mode","authors":"Rachel D. Martin, P. Unwin","doi":"10.1039/A707984B","DOIUrl":"https://doi.org/10.1039/A707984B","url":null,"abstract":"The substrate-generation–tip-collection (SG–TC) mode of the scanning electrochemical microscope (SECM) is used as a new approach to investigate the kinetics of EC processes. Under the conditions of interest, a species O is generated at a macroscopic substrate (generator) electrode, with potential-step control, through the diffusion-limited electrolysis of a solution species R (E step). As O diffuses away from the generator, it undergoes a first order chemical reaction in solution (C step). A fraction of O is collected by electrolysis back to R at an externally biased ultramicroelectrode (UME), positioned directly over the substrate. This promotes the diffusional feedback of R to the substrate. Theory for the problem, relating the time-dependent tip current response to the rate constant for the C step and the tip–substrate electrode separation is developed numerically. Results of the calculations illustrate how the characteristic features of the tip current transients: peak current, peak time and post-half-peak time, depend on the kinetics of the C step and the inter-electrode separation. It is shown that both the kinetics and tip–substrate separation can be determined independently from a single transient by simply measuring the peak current and peak time. The theoretical results are validated experimentally through model studies of the oxidative deamination of N,N,-dimethyl-p-phenylenediamine (DMPPD) in aqueous solution at high pH. The effective second-order rate constant for the deamination step is in excellent agreement with values measured by alternative methods.","PeriodicalId":17286,"journal":{"name":"Journal of the Chemical Society, Faraday Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87790456","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: 45

Satellite hole investigation of binding mechanism of dipyrrometheneboron difluoride derivative and oligonucleotide in glycerol–water glass 二吡咯甲基二氟化硼衍生物与寡核苷酸在甘油-水玻璃上结合机理的卫星空穴研究

Journal of the Chemical Society, Faraday Transactions Pub Date : 1998-01-01 DOI: 10.1039/A800325D

C. Kuo, C. Chiang, Jenwei Yu, K. Peck, Ta-Chau Chang

{"title":"Satellite hole investigation of binding mechanism of dipyrrometheneboron difluoride derivative and oligonucleotide in glycerol–water glass","authors":"C. Kuo, C. Chiang, Jenwei Yu, K. Peck, Ta-Chau Chang","doi":"10.1039/A800325D","DOIUrl":"https://doi.org/10.1039/A800325D","url":null,"abstract":"The satellite holes in hole burned (HB) spectra have been used to study the binding modes of chromophore–oligonucleotide interactions. Substantial differences of several distinct satellite holes of 4,4-difluoro-5-(4-phenyl-1,3-butadienyl)-4-bora-3a,4a-diaza-s-indacene-3-propionic acid, succinimidyl ester (BODIPY591) chemically bound to an oligonucleotide of ten bases ofthymidine deoxyribonucleotides, d(T10), doped in glycerol–water (Gl–H2O) glass are observed. Normal mode calculations fordipyrrometheneboron difluoride (BODIPY) and an HB study of the BODIPY591 derivative have been conducted to help with vibrational mode assignments. The lack of appreciable perturbations on the vibrations of the diene chain and the phenyl group implies that these groups are much less perturbed upon interacting with d(T10). However, significant frequency differences for several N2BF2 modes indicate that the geometry of the N2BF2 moiety is dramatically perturbed upon interacting with d(T10). Our results suggest that the central ring of the BODIPY moiety is the main binding site and the electrostatic interaction between the BF2 group of BODIPY591 and the NH group of d(T10), as well as the stacking of the aromatic rings between BODIPY and thymine, are the most probable binding mechanisms.","PeriodicalId":17286,"journal":{"name":"Journal of the Chemical Society, Faraday Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87404247","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: 6

Rate constants and equilibria of monochelate formation of iron(III) with 2-acetylcyclohexanone 铁(III)与2-乙酰环己酮单螯合反应的速率常数和平衡

Journal of the Chemical Society, Faraday Transactions Pub Date : 1998-01-01 DOI: 10.1039/A800521D

C. Blanco, Antonio Rojas

引用次数: 9

Emergence of isoperichoric focusing in multicomponent colloidal particle dispersion at sedimentation equilibrium 多组分胶体颗粒在沉降平衡时分散时出现等周线聚焦

Journal of the Chemical Society, Faraday Transactions Pub Date : 1998-01-01 DOI: 10.1039/A804997A

J. Janča, N. Caron, N. Gospodinova

引用次数: 3

Mutual diffusion in aqueous solution of ethylene glycol oligomers at 25 °C 乙二醇低聚物在25℃水溶液中的相互扩散

Journal of the Chemical Society, Faraday Transactions Pub Date : 1998-01-01 DOI: 10.1039/A803567I

L. Paduano, R. Sartorio, G. D’Errico, V. Vitagliano

引用次数: 30

Vanadium(IV) complexes with picolinic acids in NaY zeolite cages Synthesis, characterization and catalytic behaviour NaY分子筛笼中吡啶酸与钒配合物的合成、表征及催化行为

Journal of the Chemical Society, Faraday Transactions Pub Date : 1998-01-01 DOI: 10.1039/A706679A

A. I. Kozlov, K. Asakura, Y. Iwasawa

引用次数: 21

Structural study of mesoporous titania and titanium–stearic acid complex prepared from titanium alkoxide 醇钛制备介孔二氧化钛和硬脂酸钛配合物的结构研究

Journal of the Chemical Society, Faraday Transactions Pub Date : 1998-01-01 DOI: 10.1039/A804984J

Ryōji Takahashi, Shoichi Takenaka, S. Sato, T. Sodesawa, K. Ogura, K. Nakanishi

引用次数: 41

Diffusion of weak acids in salt solutions Maleic acid+NaCl+water 弱酸在盐溶液中的扩散马来酸+NaCl+水

Journal of the Chemical Society, Faraday Transactions Pub Date : 1998-01-01 DOI: 10.1039/A800424B

S. Wright, D. G. Leaist

{"title":"Diffusion of weak acids in salt solutions Maleic acid+NaCl+water","authors":"S. Wright, D. G. Leaist","doi":"10.1039/A800424B","DOIUrl":"https://doi.org/10.1039/A800424B","url":null,"abstract":"A Taylor dispersion tube has been used to measure binary mutual diffusion in aqueous solutions of partially dissociated maleic acid (H2MH++HM-). The diffusion coefficients of the molecular acid and the hydrogen maleate ion are estimated from the results. To investigate the effects of added salt on the transport of a weak electrolyte, quaternary mutual diffusion coefficients are reported for aqueous maleic acid+NaCl solutions. The cross-diffusion coefficients for this system indicate that the gradient in maleic acid drives large coupled flows of NaCl and HCl components. Nernst–Planck equations are used to interpret these results. The analysis shows that the addition of NaCl leads to a dramatic increase in the rate of diffusion of H+ ions because they are no longer required to diffuse at the same speed as the less-mobile HM- ions to maintain electroneutrality. Also, the electric field generated by the diffusing acid drives a large counter-current coupled flow of Na+ ions and a large co-current coupled flow of Cl- ions. Each mole of diffusing maleic acid co-transports up to 5 mol HCl and counter-transports up to 1.5 mol NaCl. The results for the aqueous maleic acid+NaCl solutions provide a guide to the diffusion behaviour of the environmentally important SO2+seawater system.","PeriodicalId":17286,"journal":{"name":"Journal of the Chemical Society, Faraday Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86161292","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: 6