Journal of The Chemical Society A: Inorganic, Physical, Theoretical最新文献_第2页

The uncatalysed and metal-ion catalysed decarboxylation of 3-oxoglutaric acid: a model for an enzyme system 3-氧戊二酸的非催化和金属离子催化脱羧:一种酶系统模型

Journal of The Chemical Society A: Inorganic, Physical, Theoretical Pub Date : 1971-01-01 DOI: 10.1039/J19710003639

R. Hay, K. N. Leong

{"title":"The uncatalysed and metal-ion catalysed decarboxylation of 3-oxoglutaric acid: a model for an enzyme system","authors":"R. Hay, K. N. Leong","doi":"10.1039/J19710003639","DOIUrl":"https://doi.org/10.1039/J19710003639","url":null,"abstract":"The uncatalysed decarboxylation of 3-oxoglutaric acid, HO2C·CH2·CO·CH2·CO2H → CH3·CO·CH2·CO2H + CO2 has been studied at 42°. The rate constants for the un-ionised acid, the monoanion, and the dianion are 12 × 10–3 min–1, 45 × 10–3 min–1, and 2·75 × 10–3 min–1 respectively. Because of the higher reactivity of the monoanion, the pH-rate profile for the uncatalysed decarboxylation is bell-shaped with a rate maximum at pH 3·5 (l= 0·1M). The enhanced reactivity of the monoanion appears to be due to intramolecular hydrogen bonding between the carbonyl group and the un-ionised carboxy-group. The practical ionisation constants of 3-oxoglutaric acid are pK1= 3·23 and pK2= 4·27 at 0·01M. The decarboxylation of 3-oxoglutaric acid, unlike that of acetoacetic acid, is catalysed by transition-metal ions, so that in the presence of metal ions there is a rapid loss of one molecular equivalent of carbon dioxide followed by a slower loss of a second molecular equivalent in the uncatalysed reaction. The catalytic effects of copper(II), nickel(II), and manganese(II) have been studied in some detail. It has been found that 2,2′-bipyridyl which is capable of π-bonding with the metal ions enhances the catalytic activity of manganese(II) by a factor of 10 while the effect with copper(II) and nickel(II) is less marked (ca. 2 times). The possible significance of these effects in the action of the metal-activated decarboxylases is discussed, as manganese(II) is the biologically important metal ion in the enzymatic reactions.","PeriodicalId":17321,"journal":{"name":"Journal of The Chemical Society A: Inorganic, Physical, Theoretical","volume":"45 1","pages":"3639-3647"},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79805390","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: 12

Co-ordination compounds of indium. Part XI. The stepwise one-electron reduction of some neutral indium(III) complexes 铟配位化合物。一些中性铟(III)配合物的逐步单电子还原

Journal of The Chemical Society A: Inorganic, Physical, Theoretical Pub Date : 1971-01-01 DOI: 10.1039/J19710003100

D. G. Tuck, M. K. Yang

引用次数: 8

Molecular structure of bis(trifluoromethyl)nitroxyl: an electron diffraction study 二(三氟甲基)硝基的分子结构:电子衍射研究

Journal of The Chemical Society A: Inorganic, Physical, Theoretical Pub Date : 1971-01-01 DOI: 10.1039/J19710000478

C. Glidewell, D. Rankin, A. Robiette, G. Sheldrick, S. M. Williamson

引用次数: 9

An ab initio study of the bonding in phosphine borane, trifluorophosphine broane and trifluorophosphine oxide 磷硼烷、三氟膦溴和三氟膦氧化物键合的从头算研究

Journal of The Chemical Society A: Inorganic, Physical, Theoretical Pub Date : 1971-01-01 DOI: 10.1039/J19710000664

I. H. Hillier, V. Saunders

引用次数: 18

Complexes of Bi- and ter-valent nickel with olefinic ditertiary arsines 二价和三价镍与烯烃己用胂的配合物

Journal of The Chemical Society A: Inorganic, Physical, Theoretical Pub Date : 1971-01-01 DOI: 10.1039/J19710000536

M. Bennett, J. Wild

{"title":"Complexes of Bi- and ter-valent nickel with olefinic ditertiary arsines","authors":"M. Bennett, J. Wild","doi":"10.1039/J19710000536","DOIUrl":"https://doi.org/10.1039/J19710000536","url":null,"abstract":"Cobalt(II) salts react with 1,2-bis(dimethylarsino)ethylene (edas)(ca. 90%trans, 10%cis) under u.v. irradiation to give complexes of cis-edas in good yield. The intermediate complexes of trans-edas are generally unstable, but a black compound Col2(trans-edas)2 with one unpaired electron can be isolated; this probably contains bridging ligand groups in a polymeric structure. The cobalt(II) complexes CoX2(cis-edas)2(X = Cl, Br, I, or NO3), which have one unpaired electron, are probably five-co-ordinate in solution and tetragonally distorted octahedral in the solid state. The complex CoCl2(cis-edas) appears to consist of the planar cation [Co(cis-edas)2]2+ and the tetrahedral anion [CoCl4]2– in the solid state, but attempts to prepare [Co(cis-edas)3]2+ give only the tervalent derivative [Co(cis-edas)3]3+. The cobalt(II) halogeno-complexes of cis-edas are readily oxidised to cobalt(III) complexes of the type [CoX2(cis-edas)2]Y [X = Cl or Br; Y = Cl, Br, or PF6; X = NCS, Y = PF6 or Co(SCN)4] The chemical and physical properties of the cobalt–cis-edas complexes are generally very like those of the analogous complexes of o-phenylenebis(dimethylarsine).","PeriodicalId":17321,"journal":{"name":"Journal of The Chemical Society A: Inorganic, Physical, Theoretical","volume":"23 1","pages":"536-544"},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81270039","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: 9

Crystal structure of tri-µ-carbonyl-pentacarbonylbis-(π-cyclopentadienylrhodio)di-iron(Rh–Rh)(Fe–Fe)(4Rh–Fe), (π-C5H5)2Rh2Fe2(CO)8 三-微羰基-五羰基双-(π-环戊二烯基铑)二铁(Rh-Rh)(Fe-Fe)(4Rh-Fe)， (π-C5H5)2Rh2Fe2(CO)的晶体结构

Journal of The Chemical Society A: Inorganic, Physical, Theoretical Pub Date : 1971-01-01 DOI: 10.1039/J19710002170

M. R. Churchill, M. V. Veidis

{"title":"Crystal structure of tri-µ-carbonyl-pentacarbonylbis-(π-cyclopentadienylrhodio)di-iron(Rh–Rh)(Fe–Fe)(4Rh–Fe), (π-C5H5)2Rh2Fe2(CO)8","authors":"M. R. Churchill, M. V. Veidis","doi":"10.1039/J19710002170","DOIUrl":"https://doi.org/10.1039/J19710002170","url":null,"abstract":"The molecular structure of (π-C5H5)2Rh2Fe2(CO)8, has been determined from X-ray diffraction studies. The compound crystallizes in the centrosymmetric orthorhombic space group Pnma(D2h16, No. 62) with a= 17·979(15), b= 12·079(12), c= 9·386(8)A and Z= 4. A full three-dimensional analysis has led to the location of all non-hydrogen atoms. The structure has been refined by least-squares methods to R 7·90% for the 627 unique non-zero reflections. The molecule has crystallographically imposed Cs symmetry with the four metal atoms defining an irregular tetrahedron with Rh–Rh 2·648(3), Rh–Fe 2·570(5)–2·598(5), and Fe–Fe 2·539(7)A. The π-C5H5 ligands and a bridging carbonyl group are associated with the two rhodium atoms while there are three terminal CO ligands attached to Fe(1) and two to Fe(2).An unusual feature of the structure is the presence of two asymmetric carbonyl bridges, Fe(2)–CO–Rh and Fe(2)–CO–Rh′, with Fe–C 1·79(4) and Rh–C 2·18(3)A. The overall disposition of ligands around the tetrahedral metal-atom core is such that it proves impossible to assign 18 outer valence electrons to each metal atom.","PeriodicalId":17321,"journal":{"name":"Journal of The Chemical Society A: Inorganic, Physical, Theoretical","volume":"41 1","pages":"2170-2173"},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81703980","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: 12

Crystal and molecular structure of nonacarbonyl(cyclododecatrienetriyl)hydrido-triangulo-triruthenium, HRu3(CO)9(C12H15): a ruthenium cluster with a novel allyl bonding system to the cyclododecatrienetriyl ligand 非羰基(环十二癸三基)羟基-三苯基-三钌，HRu3(CO)9(C12H15)的晶体和分子结构:一种与环十二癸三基配体形成新型烯丙基键合体系的钌簇

Journal of The Chemical Society A: Inorganic, Physical, Theoretical Pub Date : 1971-01-01 DOI: 10.1039/J19710003599

A. Cox, P. Woodward

{"title":"Crystal and molecular structure of nonacarbonyl(cyclododecatrienetriyl)hydrido-triangulo-triruthenium, HRu3(CO)9(C12H15): a ruthenium cluster with a novel allyl bonding system to the cyclododecatrienetriyl ligand","authors":"A. Cox, P. Woodward","doi":"10.1039/J19710003599","DOIUrl":"https://doi.org/10.1039/J19710003599","url":null,"abstract":"Crystals of the title compound are monoclinic, space group P21/a, with Z= 4 in a unit cell of dimensions: a= 11·18, b= 15·52, c= 15·48 A, and β= 114° 05′. Diffractometer data were used and the structure refined to R 0·080 for 1419 independent reflections. The ruthenium atoms each carry three carbonyl groups and are bonded to one another at the corners of an isosceles triangle. The two equal sides (2·776A) are unbridged, but the apical atom is equidistant from, and π-bonded to, three consecutive atoms C(1)–(3) of the cyclododecatrienyl ligand which thus form a π-allyl group. The outer two atoms of this π-allyl group are also each σ-bonded to one of the basal ruthenium atoms. Rearrangement of the bonds in the cyclododeca-1,5,9-triene ligand occurs, as the complex contains ethylenic links at C(6)–C(7) and at C(9)–C(10). The distance between the two basal metal atoms (2·92 A) is longer than the base–apex distances; this bond is probably hydrogen-bridged. In this compound, therefore, the cyclododecatrienyl ligand functions as a five-electron donor. The mean Ru–C and C–O distances for the carbonyl ligands are 1·87 and 1·17 A respectively.","PeriodicalId":17321,"journal":{"name":"Journal of The Chemical Society A: Inorganic, Physical, Theoretical","volume":"38 1","pages":"3599-3603"},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81735302","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: 11

The spectra and structure of aluminium chloride complexes. Part IV. Structure of higher complexes of aluminium chloride 氯化铝配合物的光谱和结构。第四部分:氯化铝高级配合物的结构

Journal of The Chemical Society A: Inorganic, Physical, Theoretical Pub Date : 1971-01-01 DOI: 10.1039/J19710003135

D. E. Jones, J. Wood

引用次数: 3

Preparation and characterisation of some nitrogen-bridged phosphorus fluorides 氮桥式氟化磷的制备与表征

Journal of The Chemical Society A: Inorganic, Physical, Theoretical Pub Date : 1971-01-01 DOI: 10.1039/J19710001547

J. Harman, M. Mccartney, D. Sharp

引用次数: 9

Reactions of trivinylborane with diboron tetrahalides: properties of some dihalogenoboryl(vinylboryl)ethanes 三乙烯基硼烷与四卤化二硼的反应:一些二卤基硼(乙烯基硼)乙烷的性质

Journal of The Chemical Society A: Inorganic, Physical, Theoretical Pub Date : 1971-01-01 DOI: 10.1039/J19710000886

A. K. Holliday, R. P. Ottley

引用次数: 6