{"title":"Substitution of aqua ligands from cis-[Pt(en)(H2O)2](ClO4)2 and cis-[Pt(dmen)(H2O)2](ClO4)2 (en = ethylenediamine, dmen = N,N′-dimethylethylenediamine) by glutathione (reduced) (GSH) in aqueous medium – A Kinetic And Mechanistic Study.","authors":"S. K. Bera, P. Sengupta, G. S. De","doi":"10.1515/IRM.2003.5.1.65","DOIUrl":"https://doi.org/10.1515/IRM.2003.5.1.65","url":null,"abstract":"","PeriodicalId":54977,"journal":{"name":"Inorganic Reaction Mechanisms","volume":"96 1","pages":"65-72"},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66816047","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}
Yessenia Ocasio-Delgado, L. Rivera-Rivera, Gisela Crespo-Roman, J. E. Cortés-Figueroa
{"title":"Site of Bond Breaking in mer-(Dihapto-[60]fullerene) (Dihapto-1, 2-Bis-(Diphenylphosphino)ethane Tricarbonyl Tungsten(0)","authors":"Yessenia Ocasio-Delgado, L. Rivera-Rivera, Gisela Crespo-Roman, J. E. Cortés-Figueroa","doi":"10.1515/IRM.2003.5.1.13","DOIUrl":"https://doi.org/10.1515/IRM.2003.5.1.13","url":null,"abstract":"","PeriodicalId":54977,"journal":{"name":"Inorganic Reaction Mechanisms","volume":"5 1","pages":"13-19"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66816044","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}
Pub Date : 2002-01-01DOI: 10.1080/1028662021000062527
A. Önal, H. Isci, Ş. Ö. Yaman
One-electron constant potential electrolysis of tetraethylammonium tris(ethylxanthato)nickelate(II), (NEt 4 )[Ni(S 2 COEt) 3 ] and bis(ethylxanthato)nickel(II), Ni(S 2 COEt) 2 , at their lowest oxidation peak potentials, were followed by in situ UV-VIS spectrophotometry, in acetonitrile at 253 K. In both cases [Ni III (S 2 COEt) 3 ] complex formed and detected by its electronic absorption and EPR spectra. [Ni III (S 2 COEt) 3 ] slowly disproportionated to Ni(S 2 COEt) 2 and the dimer of the oxidized ethylxanthate ligand, (S 2 COEt) 2 , with a second-order rate law.
{"title":"Low-temperature Spectroelectrochemistry of Tetraethylammonium Tris(ethylxanthato)nickelate(II) and Bis(ethylxanthato)nickel(II) Complexes","authors":"A. Önal, H. Isci, Ş. Ö. Yaman","doi":"10.1080/1028662021000062527","DOIUrl":"https://doi.org/10.1080/1028662021000062527","url":null,"abstract":"One-electron constant potential electrolysis of tetraethylammonium tris(ethylxanthato)nickelate(II), (NEt 4 )[Ni(S 2 COEt) 3 ] and bis(ethylxanthato)nickel(II), Ni(S 2 COEt) 2 , at their lowest oxidation peak potentials, were followed by in situ UV-VIS spectrophotometry, in acetonitrile at 253 K. In both cases [Ni III (S 2 COEt) 3 ] complex formed and detected by its electronic absorption and EPR spectra. [Ni III (S 2 COEt) 3 ] slowly disproportionated to Ni(S 2 COEt) 2 and the dimer of the oxidized ethylxanthate ligand, (S 2 COEt) 2 , with a second-order rate law.","PeriodicalId":54977,"journal":{"name":"Inorganic Reaction Mechanisms","volume":"4 1","pages":"133-139"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59827289","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}
Pub Date : 2002-01-01DOI: 10.1080/1028662021000062581
Sukalpa Dey, P. Banerjee
The kinetics of the reaction of [Pt(digly)(H 2 O)] (where H 2 digly=glycylglycine) with imidazole, pyrazole and triazole were studied at 25°C in aqueous medium by UV-Vis. spectroscopy at I =0.1 mol dm m 3 in the range of pH=5.05-9.00. The entry of the azole bases by the substitution of aqua ligand was revealed. All the products have been characterized through CHN analysis, IR and 1 H NMR spectra. The pH variation data were fitted by a computer fit program and the reactivity of the different azole base species towards the Pt(II) substrate ascertained.
{"title":"Interaction of Some Azole Bases with Platinum(II)-Glycylglycine--Kinetics, Mechanism and Product Characterization","authors":"Sukalpa Dey, P. Banerjee","doi":"10.1080/1028662021000062581","DOIUrl":"https://doi.org/10.1080/1028662021000062581","url":null,"abstract":"The kinetics of the reaction of [Pt(digly)(H 2 O)] (where H 2 digly=glycylglycine) with imidazole, pyrazole and triazole were studied at 25°C in aqueous medium by UV-Vis. spectroscopy at I =0.1 mol dm m 3 in the range of pH=5.05-9.00. The entry of the azole bases by the substitution of aqua ligand was revealed. All the products have been characterized through CHN analysis, IR and 1 H NMR spectra. The pH variation data were fitted by a computer fit program and the reactivity of the different azole base species towards the Pt(II) substrate ascertained.","PeriodicalId":54977,"journal":{"name":"Inorganic Reaction Mechanisms","volume":"4 1","pages":"159-167"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59827953","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}
Pub Date : 2002-01-01DOI: 10.1080/1028662021000062590
G. D. Iuliis, G. Lawrance, Nicole L. Wilson
The cleavage of the RNA dimers GpA and ApUp is promoted by the inert cobalt(III) complex [Co(tren)(OH 2 )(OH)] 2+ (tren= N , N -bis(2-aminoethyl)ethane-1,2-diamine) the reactions being followed spectrophotometrically, with rate enhancements comparable to those observed for that complex reacting with the model phosphodiester bis( p -nitrophenyl)phosphate. Likewise, the labile [Cu(tach)(OH 2 )(OH)] + complex (tach=cyclohexane-1,3,5-triamine) promotes cleavage of the RNA dimer ApA and trimer ApCpC, observed using electrospray ionization mass spectrometry (ESIMS). Mixtures of ApCpC or ApA and the copper complex prepared at room temperature and examined immediately exhibit peaks assigned to the phosphodiesters and their copper complexes. After heating at elevated temperature for several hours, the ESIMS show clear evidence of cleavage, with peaks due to the parent phosphodiester and their initial complexes absent. While the metal complex promotes the reaction, cyclic phosphodiester intermediates observed also ...
惰性钴(III)配合物[Co(tren)(OH 2)(OH)] 2+ (tren= N, N -二(2-氨基乙基)乙烷-1,2-二胺)促进了RNA二聚体GpA和ApUp的裂解。分光光度法跟踪了该反应，其速率提高可与该配合物与模型磷酸二酯(对硝基苯)磷酸反应相比较。同样，通过电喷雾电离质谱(ESIMS)观察到，不稳定的[Cu(tach)(OH 2)(OH)] +配合物(tach=环己烷-1,3,5-三胺)促进RNA二聚体ApA和三聚体ApCpC的裂解。室温下制备的ApCpC或ApA与铜配合物的混合物，立即显示出磷酸二酯及其铜配合物的峰。在高温下加热数小时后，ESIMS显示出明显的解理证据，由于母体磷酸二酯及其初始配合物的峰缺失。在金属配合物促进反应的同时，环磷酸二酯中间体也被观察到。
{"title":"Metal Complex-promoted Cleavage of RNA Dimers and Trimers: Electrospray Ionisation Mass Spectrometry Evidence for Cleavage","authors":"G. D. Iuliis, G. Lawrance, Nicole L. Wilson","doi":"10.1080/1028662021000062590","DOIUrl":"https://doi.org/10.1080/1028662021000062590","url":null,"abstract":"The cleavage of the RNA dimers GpA and ApUp is promoted by the inert cobalt(III) complex [Co(tren)(OH 2 )(OH)] 2+ (tren= N , N -bis(2-aminoethyl)ethane-1,2-diamine) the reactions being followed spectrophotometrically, with rate enhancements comparable to those observed for that complex reacting with the model phosphodiester bis( p -nitrophenyl)phosphate. Likewise, the labile [Cu(tach)(OH 2 )(OH)] + complex (tach=cyclohexane-1,3,5-triamine) promotes cleavage of the RNA dimer ApA and trimer ApCpC, observed using electrospray ionization mass spectrometry (ESIMS). Mixtures of ApCpC or ApA and the copper complex prepared at room temperature and examined immediately exhibit peaks assigned to the phosphodiesters and their copper complexes. After heating at elevated temperature for several hours, the ESIMS show clear evidence of cleavage, with peaks due to the parent phosphodiester and their initial complexes absent. While the metal complex promotes the reaction, cyclic phosphodiester intermediates observed also ...","PeriodicalId":54977,"journal":{"name":"Inorganic Reaction Mechanisms","volume":"4 1","pages":"169-186"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/1028662021000062590","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59828045","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}
Pub Date : 2002-01-01DOI: 10.1080/10286620290034737
A. Bowden, J. L. Kubeika, J. Atwood
Reactions of methylating agents, MeI and Me 3 OBF 4 , with trans -Ir(CO)(Cl)(TPPTS) 2 (TPPTS=P( m -C 6 H 4 SO 3 Na) 3 ) are examined in H 2 O and DMSO. Three products are observed with MeI in water, Ir(CO)(Cl)(I)(Me)(TPPTS) 2 , Ir(CO)(Cl)(Me)(H 2 O)(TPPTS) 2 + and Ir(CO)(I)(Me)(H 2 O)(TPPTS) 2 + ; reactions in the presence of excess Cl m and I m form Ir(CO)(Cl) 2 (Me)(TPPTS) 2 and Ir(CO)(I) 2 (Me)(TPPTS) 2 , respectively. Reaction of trimethyloxonium + with trans -Ir(CO)(CI)(TPPTS) 2 produced only Ir(CO)(Cl)(Me)(H 2 O)(TPPTS) 2 + . None of the methyl compounds underwent hydrolysis or carbonylation.
{"title":"Preparation and Reactions of Methyl Iridium Complexes in Water","authors":"A. Bowden, J. L. Kubeika, J. Atwood","doi":"10.1080/10286620290034737","DOIUrl":"https://doi.org/10.1080/10286620290034737","url":null,"abstract":"Reactions of methylating agents, MeI and Me 3 OBF 4 , with trans -Ir(CO)(Cl)(TPPTS) 2 (TPPTS=P( m -C 6 H 4 SO 3 Na) 3 ) are examined in H 2 O and DMSO. Three products are observed with MeI in water, Ir(CO)(Cl)(I)(Me)(TPPTS) 2 , Ir(CO)(Cl)(Me)(H 2 O)(TPPTS) 2 + and Ir(CO)(I)(Me)(H 2 O)(TPPTS) 2 + ; reactions in the presence of excess Cl m and I m form Ir(CO)(Cl) 2 (Me)(TPPTS) 2 and Ir(CO)(I) 2 (Me)(TPPTS) 2 , respectively. Reaction of trimethyloxonium + with trans -Ir(CO)(CI)(TPPTS) 2 produced only Ir(CO)(Cl)(Me)(H 2 O)(TPPTS) 2 + . None of the methyl compounds underwent hydrolysis or carbonylation.","PeriodicalId":54977,"journal":{"name":"Inorganic Reaction Mechanisms","volume":"3 1","pages":"249-254"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/10286620290034737","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59828484","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}
Pub Date : 2002-01-01DOI: 10.1080/1028662021000003847
S. A. Farokhi, A. K. Kini, S. Nandibewoor
The kinetics of oxidation of l -hydroxyproline in aqueous alkaline medium was studied spectrophotometrically. The reaction showed first order kinetics in permanganate ion concentration and an order less than unity in l -hydroxyproline and alkali concentrations. Increasing ionic strength and decreasing dielectric constant of the medium increase the rate. The oxidation reaction proceeds via an alkali-permanganate species which forms a complex with l -hydroxyproline. The latter decomposes slowly, followed by a fast reaction between a free radical of l -hydroxyproline and another molecule of permanganate to give the products. There is a good agreement between the observed and calculated rate constants under different experimental conditions. Investigations at different temperatures allowed the determination of the activation parameters with respect to the slow step of the proposed mechanism.
{"title":"Oxidation of l -Hydroxyproline by Aqueous Alkaline Permanganate--A Kinetic Study","authors":"S. A. Farokhi, A. K. Kini, S. Nandibewoor","doi":"10.1080/1028662021000003847","DOIUrl":"https://doi.org/10.1080/1028662021000003847","url":null,"abstract":"The kinetics of oxidation of l -hydroxyproline in aqueous alkaline medium was studied spectrophotometrically. The reaction showed first order kinetics in permanganate ion concentration and an order less than unity in l -hydroxyproline and alkali concentrations. Increasing ionic strength and decreasing dielectric constant of the medium increase the rate. The oxidation reaction proceeds via an alkali-permanganate species which forms a complex with l -hydroxyproline. The latter decomposes slowly, followed by a fast reaction between a free radical of l -hydroxyproline and another molecule of permanganate to give the products. There is a good agreement between the observed and calculated rate constants under different experimental conditions. Investigations at different temperatures allowed the determination of the activation parameters with respect to the slow step of the proposed mechanism.","PeriodicalId":54977,"journal":{"name":"Inorganic Reaction Mechanisms","volume":"4 1","pages":"67-76"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/1028662021000003847","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59826913","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}
Pub Date : 2002-01-01DOI: 10.1080/1028662021000062509
Yakup Baran, P. Comba, G. Lawrance
Base hydrolysis kinetics of chloropentaaminecobalt(III) complexes of a range of acyclic and cyclic pentaamine ligands, incorporating the rigid -NH-CH 2 -C(CH 3 )(NH 2 )-CH 2 -NH- motif, which must coordinate facially in octahedral complexes, are analysed in terms of ground state structural influences on hydrolysis rates. For complexes without experimental structural data, molecular mechanics was used to predict Co-Cl and Co-N bond distances. The computed strain energies and structural parameters both isomers ( trans and cis ) of all compounds are analysed. Although sterically crowded ligands, which should favour a five-coordinate intermediate, exhibit larger k OH values, only a modest correlation between ground state Co-L distances and hydrolysis rates is found. This suggests that the structures of the transition state and/or of the five-coordinate intermediate is important.
{"title":"Trends in Base Hydrolysis Rates of Chlorocobalt(III) Complexes of a Series of Related Pentaamine Ligands","authors":"Yakup Baran, P. Comba, G. Lawrance","doi":"10.1080/1028662021000062509","DOIUrl":"https://doi.org/10.1080/1028662021000062509","url":null,"abstract":"Base hydrolysis kinetics of chloropentaaminecobalt(III) complexes of a range of acyclic and cyclic pentaamine ligands, incorporating the rigid -NH-CH 2 -C(CH 3 )(NH 2 )-CH 2 -NH- motif, which must coordinate facially in octahedral complexes, are analysed in terms of ground state structural influences on hydrolysis rates. For complexes without experimental structural data, molecular mechanics was used to predict Co-Cl and Co-N bond distances. The computed strain energies and structural parameters both isomers ( trans and cis ) of all compounds are analysed. Although sterically crowded ligands, which should favour a five-coordinate intermediate, exhibit larger k OH values, only a modest correlation between ground state Co-L distances and hydrolysis rates is found. This suggests that the structures of the transition state and/or of the five-coordinate intermediate is important.","PeriodicalId":54977,"journal":{"name":"Inorganic Reaction Mechanisms","volume":"4 1","pages":"31-47"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/1028662021000062509","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59827240","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}
Pub Date : 2002-01-01DOI: 10.1080/1028662021000062491
L. Rivera-Rivera, Frisia D. Colón-Padilla, Yessenia Ocasio-Delgado, Jomary Martínez-Rivera, Samirah Mercado-Feliciano, C. Ramos, J. E. Cortés-Figueroa
The Lewis bases triphenyl phosphine and triethyl phosphite (L) displace C 60 from ( m 2 -C 60 )W(CO) 5 to produce the complexes ( m 1 -L)W(CO) 5 . These displacement reactions were studied under conditions where the concentrations of C 60 and L were at least 50 times the concentration of ( m 2 -C 60 )W(CO) 5 . The reactions in various solvents were first order with respect to ( m 2 -C 60 )W(CO) 5 . The pseudo first order rate constant values were independent of the concentration and of the nature of L but dependent on the coordinating ability of the solvent under conditions where [C 60 ]/[L] , 0. Under conditions where 0 h [C 60 ]/[L] h 1, the pseudo first order rate constant values decrease as the values of [C 60 ]/[L] increase. Two limiting cases of an interchange displacement of C 60 from ( m 2 -C 60 )W(CO) 5 , whose relative contributions to the overall mechanism depend on the nature of the solvent, are proposed to be a solvent-assisted C 60 -W(CO) 5 bond displacement and a dissociative displacement. ...
{"title":"Kinetics and Mechanisms of Ligand Exchange Reactions on (Dihapto-Buckminsterfullerene) Pentacarbonyl Tungsten(0)","authors":"L. Rivera-Rivera, Frisia D. Colón-Padilla, Yessenia Ocasio-Delgado, Jomary Martínez-Rivera, Samirah Mercado-Feliciano, C. Ramos, J. E. Cortés-Figueroa","doi":"10.1080/1028662021000062491","DOIUrl":"https://doi.org/10.1080/1028662021000062491","url":null,"abstract":"The Lewis bases triphenyl phosphine and triethyl phosphite (L) displace C 60 from ( m 2 -C 60 )W(CO) 5 to produce the complexes ( m 1 -L)W(CO) 5 . These displacement reactions were studied under conditions where the concentrations of C 60 and L were at least 50 times the concentration of ( m 2 -C 60 )W(CO) 5 . The reactions in various solvents were first order with respect to ( m 2 -C 60 )W(CO) 5 . The pseudo first order rate constant values were independent of the concentration and of the nature of L but dependent on the coordinating ability of the solvent under conditions where [C 60 ]/[L] , 0. Under conditions where 0 h [C 60 ]/[L] h 1, the pseudo first order rate constant values decrease as the values of [C 60 ]/[L] increase. Two limiting cases of an interchange displacement of C 60 from ( m 2 -C 60 )W(CO) 5 , whose relative contributions to the overall mechanism depend on the nature of the solvent, are proposed to be a solvent-assisted C 60 -W(CO) 5 bond displacement and a dissociative displacement. ...","PeriodicalId":54977,"journal":{"name":"Inorganic Reaction Mechanisms","volume":"15 1","pages":"49-56"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59827569","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}
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