BioInorganic Reaction Mechanisms最新文献_第10页

Kinetics of the Photosubstitution of ds-Bis(benzonitrile)dichloroplatinum(II) in Chloroform ds-双(苯腈)二氯铂(II)在氯仿中的光取代动力学

BioInorganic Reaction Mechanisms Pub Date : 1999-01-01 DOI: 10.1515/irm-1999-0206

E. M. Jaryszak, Son L. Phan, P. Hoggard

引用次数: 7

The Dependence of the Copper Dissociation Rate Constants from Human(Serum)- and Ονο-Transferrin on pH and the Anions 人(血清)-和Ονο-Transferrin中铜解离速率常数对pH和阴离子的依赖

BioInorganic Reaction Mechanisms Pub Date : 1999-01-01 DOI: 10.1515/irm-1999-0205

J. Hirose, I. Fujiwara, K. Iio, Shinichi Masunari, M. Minakami, L. Messori, K. Hiromi

{"title":"The Dependence of the Copper Dissociation Rate Constants from Human(Serum)- and Ονο-Transferrin on pH and the Anions","authors":"J. Hirose, I. Fujiwara, K. Iio, Shinichi Masunari, M. Minakami, L. Messori, K. Hiromi","doi":"10.1515/irm-1999-0205","DOIUrl":"https://doi.org/10.1515/irm-1999-0205","url":null,"abstract":"Abstract Transferrin is an iron carrier protein. It is known that the conformational change in the protein moiety induced by binding of nonsynergistic anions influences the metal release rate constants from metal transferrins. The copper dissociation rate constants of dicupric human(serum)-transferrin and ovo-transferrin were measured under the conditions of various pHs and ionic strengths to estimate the residues which interact with nonsynergistic anions. The pH and the ionic strength dependence of the copper dissociation rate constants in the N-lobe of serum (human)-transferrin and both lobes of ovo-Tf clearly show that some residue which has a pKa around 6.0 is involved in the binding of nonsynergistic anions and accelerating the copper dissociation rate. In the C-lobe of serum(human)-Tf, the copper dissociation rate constants were almost independent of pH between pH 7.0 and 9.0, but the dissociation rates were constantly accelerated by the presence of 0.1 Μ KCl. This behavior suggests that the residue in the C-lobe of serum(human)-Tf is constantly protonated between pH 7.0 and 9.0 and is involved in the binding of nonsynergistic anions binding site.","PeriodicalId":8996,"journal":{"name":"BioInorganic Reaction Mechanisms","volume":"1 1","pages":"121 - 128"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77782793","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

Reaction between [Ru(H2O)6]2+ and DMF: A Complete Volume Profile of a Monocomplex Formation Reaction on a d6 Low Spin Aquaion [Ru(H2O)6]2+与DMF的反应:d6低自旋水溶液中单络合物形成反应的完整体积分布

BioInorganic Reaction Mechanisms Pub Date : 1999-01-01 DOI: 10.1515/irm-1999-0307

N. Aebischer, A. Merbach

{"title":"Reaction between [Ru(H2O)6]2+ and DMF: A Complete Volume Profile of a Monocomplex Formation Reaction on a d6 Low Spin Aquaion","authors":"N. Aebischer, A. Merbach","doi":"10.1515/irm-1999-0307","DOIUrl":"https://doi.org/10.1515/irm-1999-0307","url":null,"abstract":"Abstract The reaction between [Ru(H2O)6]2+ and dimethylformamide (DMF) was studied as a function of the temperature and the pressure at pH 1. When a slight excess of Ru aquaion is used, [Ru(H2O)5DMF]2+ is the only product of the reaction observed in the NMR spectra and the DMF is bound through the oxygen atom. From variable temperature experiments, the rate constants, activation enthalpies and entropies for the formation and the dissociation of the monocomplex were determined. These are as follows: 104 x kf298=(8.2 ± 0.4) kg mol-1 s-1 ΔΗ☨f= 83.6 ± 3 k J mol-1 Δ S☨f = -23.7 ± 10 J K-1mol-1 for the formation reaction, 103 x kd298 = (1.10 ± 0.04) s-1 ΔΗ☨f= 90.2 ± 2 kJ mol-1 ΔS☨f, = +1.0 ± 7 J Κ-1 mol -1 for the dissociation reaction. The thermodynamic parameters (equilibrium constant at 298.15 K, reaction enthalpy and entropy) were also determined:K298eq = 0.74 ± 0.02 kg mol-1 , ΔH0 = -6.6 ± 2 k j mol-1 , ΔS0 =-24.7 ± 6 JK-1. The kf value is similar to the previously reported rate constants for monocomplex formation reactions with other ligands and confirms that the entering ligand has no effect on the rate. From variable pressure experiments, the activation volumes for the formation and the dissociation reactions and the reaction volume were determined: ΔVf☨ = +2.7 ± 0.6 cm3 mol-1 , ΔVd☨= 0.9 ± 0.7 cm3 mol-1 , ΔV° = +3.6 ± 0 . 9 cm3 mol -1 respectively. These results show that the volume of the transition state is intermediate between the volume of the reactants and the volume of the products. It demonstrates that the mechanism is the same as for the water exchange on [Ru(H2O)6 ] 2+ , i.e. an Id mechanism. Contraction of the bonds between Ru and the spectator ligands at the transition state may explain the abnormally small activation volumes. The need of theoretical calculations on these systems is emphasized.","PeriodicalId":8996,"journal":{"name":"BioInorganic Reaction Mechanisms","volume":"5 1","pages":"233 - 246"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83252664","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: 3

Kinetics and Mechanism of the Chromium(VI) Oxidation of Formic Acid in the Presence of Picolinic Acid and in the Presence and Absence of Surfactants 甲酸在吡啶酸和表面活性剂存在和不存在下的铬(VI)氧化动力学和机理

BioInorganic Reaction Mechanisms Pub Date : 1999-01-01 DOI: 10.1515/irm-1999-0210

A. Das

{"title":"Kinetics and Mechanism of the Chromium(VI) Oxidation of Formic Acid in the Presence of Picolinic Acid and in the Presence and Absence of Surfactants","authors":"A. Das","doi":"10.1515/irm-1999-0210","DOIUrl":"https://doi.org/10.1515/irm-1999-0210","url":null,"abstract":"Abstract The kinetics and mechanism of picolinic acid (PA)- catalysed oxidation of formic acid have been studied in aqueous HClO4 media under the experimental conditions, 103[Cr(VI)]T = 0.67-2.67 mol dm-3, [PA]T = 0.01-0.12 mol dm-3, [HCO2H]T = 0.1-0.8 mol dm-3, [H+] = 0.35-1.5 mol dm-3,1 = 1.5 mol dm-3 in the temperature range 25-40° C. The kinetic parameters of the catalysed path have been compared with those of the relatively slower uncatalysed path which proceed parallelly with the catalysed path. In the catalysed path, Cr(VI)-PA cyclic complex formed at the pre-equilibrium step receives a nucleophilic attack at the Cr(VI) centre by the substrate leading to a ternary complex with the release of a proton in a reversible path. Then the ternary complex experiences the redox decomposition at the rate-determining step giving rise to Cr(IV)-PA complex and CO2. Then the Cr(IV)-PA complex reacts faster ultimately giving rise to Cr(III)-PA complex. The anionic surfactant sodium dodecyl sulfate (SDS) catalyses both the uncatalysed and catalysed paths in aqueous HClO4 media while the cationic surfactant cetyl pyridinium chloride (CPC) inhibits the reactions in aqueous H2SO4 media. In the presence of the surfactants, applicability of the Piszkiewicz model has been tested for the ΡΑ-catalysed path. Micellar effects are in conformity with the proposed mechanism.","PeriodicalId":8996,"journal":{"name":"BioInorganic Reaction Mechanisms","volume":"85 1","pages":"161 - 168"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80008465","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: 19

Thermo-kinetic and Spectral Studies of Lanthanide(III) Complexes with 2-Hydroxy-l -benzylidene-2-furoyl Hydrazine 镧系(III)与2-羟基- 1 -苄基-2-呋喃肼配合物的热动力学和光谱研究

BioInorganic Reaction Mechanisms Pub Date : 1999-01-01 DOI: 10.1515/irm-1999-0305

P. B. Maravalli, T. R. Goudar

引用次数: 1

Kinetics and Mechanism of Chromium(III) Catalysed Oxidation of Propan-1-ol and Butan-1-ol by Cerium(IV) in Aqueous Sulfuric acid Media 硫酸水溶液中铬(III)催化铈(IV)氧化丙-1-醇和丁-1-醇的动力学及机理

BioInorganic Reaction Mechanisms Pub Date : 1999-01-01 DOI: 10.1515/irm-1999-0211

A. Das, S. Mondal, D. Kar, M. Das

引用次数: 2

On the Mechanism of Oxidation of Formate by Ni(III) (meso-5,7,7,12,14,14-hexamethy 1-1,4,8,11 - tetraazacyclotetradecane) in Aqueous Solutions Ni(III)(中位-5,7,7,12,14,14-六聚体- 1,1,4,8,11 -四氮杂环十四烷)在水溶液中氧化甲酸盐的机理研究

BioInorganic Reaction Mechanisms Pub Date : 1999-01-01 DOI: 10.1515/irm-1999-0303

A. Meshulam, A. Masarwa, H. Cohen, D. Meyerstein

引用次数: 1

Kinetic and Mechanistic Studies on the Interaction of Adenosine with Diaquaethylenediamineplatinum(II) Ion 腺苷与二乙二胺铂(II)离子相互作用的动力学和机理研究

BioInorganic Reaction Mechanisms Pub Date : 1999-01-01 DOI: 10.1515/irm-1999-0302

S. Ghosh, G. S. De, A. Ghosh

引用次数: 1

Substitution Reactions on Pd(II) L-Histidine-diaqua Complexes: Comparative View from Chloride to Nucleobases and Dinucleotides Pd(II) l -组氨酸-二水络合物的取代反应:从氯化物到核碱基和二核苷酸的比较

BioInorganic Reaction Mechanisms Pub Date : 1999-01-01 DOI: 10.1515/irm-1999-0304

Nausica De Barrios, Gabriel González, A. Grandas, Manuel A Martínez, V. Moreno

引用次数: 6

Kinetics and Mechanism of Oxidation of Tellurium(IV) by Alkaline Diperiodatonickelate(IV) 碱性双碘酸盐氧化碲(IV)的动力学及机理

BioInorganic Reaction Mechanisms Pub Date : 1999-01-01 DOI: 10.1515/irm-1999-0208

A. L. Harihar, M. R. Kembhavi, S. Nandibewoor

引用次数: 5