After exposure of phosphoryl chloride to 60Co γ-rays at 77 K, three radical species were detected. One, having a large 31P hyperfine coupling of about 1350 G is thought to be POCl3–, having two strongly coupled chlorine atoms (Aiso 66 G) and one weakly coupled chlorine atom (Aisoca. 20 G). The second species, thought to be POCl2 gave an axially symmetric spectrum at 77 K, but this became isotropic on warming the sample to 100 K, when Aiso(31P) was 759 G and Aiso(35Cl) was 18 G.The third major species, thought to be PO2Cl2, had Aiso(31P) 43 G and Aiso(35Cl) 3 G. This species was probably formed from HPO2Cl2 impurity.With similar treatment, phosphorus trichloride gave PCl2 and PCl4 radicals whilst the pentachloride gave PCl4 and an unidentified radical containing two chlorine atoms.
{"title":"Unstable intermediates. Part XCV. Electron spin resonance spectra assigned to the radicals POCl3–, POCl2, PO2Cl2, PCl2, and PCl4 in γ-irradiated POCl3, PCl3, and PCl5","authors":"A. Begum, M. Symons","doi":"10.1039/J19710002065","DOIUrl":"https://doi.org/10.1039/J19710002065","url":null,"abstract":"After exposure of phosphoryl chloride to 60Co γ-rays at 77 K, three radical species were detected. One, having a large 31P hyperfine coupling of about 1350 G is thought to be POCl3–, having two strongly coupled chlorine atoms (Aiso 66 G) and one weakly coupled chlorine atom (Aisoca. 20 G). The second species, thought to be POCl2 gave an axially symmetric spectrum at 77 K, but this became isotropic on warming the sample to 100 K, when Aiso(31P) was 759 G and Aiso(35Cl) was 18 G.The third major species, thought to be PO2Cl2, had Aiso(31P) 43 G and Aiso(35Cl) 3 G. This species was probably formed from HPO2Cl2 impurity.With similar treatment, phosphorus trichloride gave PCl2 and PCl4 radicals whilst the pentachloride gave PCl4 and an unidentified radical containing two chlorine atoms.","PeriodicalId":17321,"journal":{"name":"Journal of The Chemical Society A: Inorganic, Physical, Theoretical","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86274107","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}
A voltammetric study of the complex previously formulated as [Re{S2C2(CN)2}2]22– has shown that it must be reformulated as [Re{S2C2(CN)2}2]44–, which undergoes one one-electron reduction and two one-electron oxidation processes. Oxidation of [Re{S2C2(CN)2}3]2– with iodine afforded [ReO{S2C2(CN)2}2]–, which may be reduced voltammetrically to a dianion.
{"title":"Transition-metal dithiolene complexes. Part XX. Dicyano-1,2-dithiolene complexes of rhenium","authors":"N. Connelly, C. J. Jones, J. McCleverty","doi":"10.1039/J19710000712","DOIUrl":"https://doi.org/10.1039/J19710000712","url":null,"abstract":"A voltammetric study of the complex previously formulated as [Re{S2C2(CN)2}2]22– has shown that it must be reformulated as [Re{S2C2(CN)2}2]44–, which undergoes one one-electron reduction and two one-electron oxidation processes. Oxidation of [Re{S2C2(CN)2}3]2– with iodine afforded [ReO{S2C2(CN)2}2]–, which may be reduced voltammetrically to a dianion.","PeriodicalId":17321,"journal":{"name":"Journal of The Chemical Society A: Inorganic, Physical, Theoretical","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86451065","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}
H. Hill, J. M. Pratt, M. P. O'riordan, F. R. Williams, ROBERT J. P. Williams
Controlled potential coulometric analysis has been used to investigate the reduction of alkyl halides in the presence of vitamin B12a. At voltages greater than the half-wave potential of the alkyl halide the reduction is a two-electron process. Below this half-wave potential the reduction is a one-electron reaction. The importance of these observations lies in considerations of the reaction mechanisms of reductions catalysed by vitamin B12 in both model and biological systems.
{"title":"The chemistry of vitamin B12. Part XV. Catalysis of alkyl halide reduction by vitamin B12a: studies using controlled potential reduction","authors":"H. Hill, J. M. Pratt, M. P. O'riordan, F. R. Williams, ROBERT J. P. Williams","doi":"10.1039/J19710001859","DOIUrl":"https://doi.org/10.1039/J19710001859","url":null,"abstract":"Controlled potential coulometric analysis has been used to investigate the reduction of alkyl halides in the presence of vitamin B12a. At voltages greater than the half-wave potential of the alkyl halide the reduction is a two-electron process. Below this half-wave potential the reduction is a one-electron reaction. The importance of these observations lies in considerations of the reaction mechanisms of reductions catalysed by vitamin B12 in both model and biological systems.","PeriodicalId":17321,"journal":{"name":"Journal of The Chemical Society A: Inorganic, Physical, Theoretical","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86089327","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}
The structure of potassium µ-nitrido-bis[aquotetrachlororuthenate(IV)], K3[Ru2NCl8(H2O)2], has been determined by thee-dimensional X-ray crystal structure analysis. The compound crystallises in the monoclinic space group C2/m with Z= 2 in a unit-cell of dimensions a= 15·89, b= 7·34, c= 8·16 A, β= 120·4°. Full-matrix least-squares refinement, with 697 visually estimated reflections, gave a final R value of 0·088.The structure contains the nitrido-bridged complex ion [Ru2NCl8(H2O)2]3–, which has 2/m crystallographic symmetry with the nitrogen atom lying on a centre of symmetry. The Ru–N distances are very short, 1·720 A, indicating multiple bonding. The water molecules are trans to the nitrogen, with a fairly long Ru–O (water) distance of 2·18 A. The four chlorines about each ruthenium are bent away from the nitrogen and towards the water molecule, such that the N–Ru–Cl angles are ca. 95°. The two independent Ru–Cl distances of 2·364 and 2·367 A are normal. The potassium ions are co-ordinated to eight chlorines at distances in the range 3·20–3·36 A.
{"title":"Crystal structure of potassium µ-nitrido-bis[aquotetrachlororuthenate(IV)]","authors":"M. Ciechanowicz, A. C. Skapski","doi":"10.1039/J19710001792","DOIUrl":"https://doi.org/10.1039/J19710001792","url":null,"abstract":"The structure of potassium µ-nitrido-bis[aquotetrachlororuthenate(IV)], K3[Ru2NCl8(H2O)2], has been determined by thee-dimensional X-ray crystal structure analysis. The compound crystallises in the monoclinic space group C2/m with Z= 2 in a unit-cell of dimensions a= 15·89, b= 7·34, c= 8·16 A, β= 120·4°. Full-matrix least-squares refinement, with 697 visually estimated reflections, gave a final R value of 0·088.The structure contains the nitrido-bridged complex ion [Ru2NCl8(H2O)2]3–, which has 2/m crystallographic symmetry with the nitrogen atom lying on a centre of symmetry. The Ru–N distances are very short, 1·720 A, indicating multiple bonding. The water molecules are trans to the nitrogen, with a fairly long Ru–O (water) distance of 2·18 A. The four chlorines about each ruthenium are bent away from the nitrogen and towards the water molecule, such that the N–Ru–Cl angles are ca. 95°. The two independent Ru–Cl distances of 2·364 and 2·367 A are normal. The potassium ions are co-ordinated to eight chlorines at distances in the range 3·20–3·36 A.","PeriodicalId":17321,"journal":{"name":"Journal of The Chemical Society A: Inorganic, Physical, Theoretical","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86342914","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}
Crystals of CuCIL3, CuBrL3, and Ir(NO)L3, isomorphous with the trigonal polymorph of Pt(CO)L3(L = PPh3), represent further examples of unbalanced packing of chiral molecules. The structure of Ir(NO)(PPh3)3 has been fully determined from 1929 independent reflexions measured by counter methods. This complex crystallizes in space group P3 and has a unit cell of dimensions: a= 19·94(1), and c= 10·780(5)A, with Z= 3. The structure has been refined by full matrix least-squares to a final R of 0·0475. The absolute configuration of the crystal sample has been determined unambiguously and designated R,S,S. The three independent molecules present in the unit cell each possess C3 symmetry and display almost the same conformation. The Ir–N, Ir–P, and N–O bond lengths are 1·67(2), 2·31(1), and 1·24(3)A. The N–Ir–P and P–Ir–P angles are 116·8(5) and 101·3(6)°; there is indirect evidence of linearity in the Ir–N–O interaction.
{"title":"Further examples of unbalanced packing of chiral molecules and the crystal and molecular structure of tris(triphenylphosphine)nitrosyl-iridium","authors":"V. Albano, P. L. Bellon, M. Sansoni","doi":"10.1039/J19710002420","DOIUrl":"https://doi.org/10.1039/J19710002420","url":null,"abstract":"Crystals of CuCIL3, CuBrL3, and Ir(NO)L3, isomorphous with the trigonal polymorph of Pt(CO)L3(L = PPh3), represent further examples of unbalanced packing of chiral molecules. The structure of Ir(NO)(PPh3)3 has been fully determined from 1929 independent reflexions measured by counter methods. This complex crystallizes in space group P3 and has a unit cell of dimensions: a= 19·94(1), and c= 10·780(5)A, with Z= 3. The structure has been refined by full matrix least-squares to a final R of 0·0475. The absolute configuration of the crystal sample has been determined unambiguously and designated R,S,S. The three independent molecules present in the unit cell each possess C3 symmetry and display almost the same conformation. The Ir–N, Ir–P, and N–O bond lengths are 1·67(2), 2·31(1), and 1·24(3)A. The N–Ir–P and P–Ir–P angles are 116·8(5) and 101·3(6)°; there is indirect evidence of linearity in the Ir–N–O interaction.","PeriodicalId":17321,"journal":{"name":"Journal of The Chemical Society A: Inorganic, Physical, Theoretical","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82693046","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}
The electronic structures of halogenopentacarbonyl-manganese and -rhenium are discussed by application of the self-consistent charge and configuration molecular orbital (SCCC–MO) method. Good correlation between calculated quantities such as orbital energies and overlap populations and experimental quantities such as photoionization spectra and vibrational force constants are obtained. The relative reactivities of this series to carbonylsubstitution which proceeds by a dissociative mechanism is also found to correlate with M–C overlap populations in a satisfactory manner.
{"title":"Molecular orbital theory of organometallic compounds. Part XIII. Electronic structures and reactivities of halogenopentacarbonyl compounds of manganese and rhenium","authors":"David A. Brown, W. J. Chambers","doi":"10.1039/J19710002083","DOIUrl":"https://doi.org/10.1039/J19710002083","url":null,"abstract":"The electronic structures of halogenopentacarbonyl-manganese and -rhenium are discussed by application of the self-consistent charge and configuration molecular orbital (SCCC–MO) method. Good correlation between calculated quantities such as orbital energies and overlap populations and experimental quantities such as photoionization spectra and vibrational force constants are obtained. The relative reactivities of this series to carbonylsubstitution which proceeds by a dissociative mechanism is also found to correlate with M–C overlap populations in a satisfactory manner.","PeriodicalId":17321,"journal":{"name":"Journal of The Chemical Society A: Inorganic, Physical, Theoretical","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90379183","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}
The isomerization of n-butenes has been studied in a static system using as catalysts zeolites of the 13X-type with different extents of replacement of sodium ions by nickel ions. The presence of nickel enhances the catalytic activity considerably, comparable reaction rates with the nickel-containing zeolites being observed at temperatures 200 K lower than with the parent Na13X.A striking feature of the but-1-ene reaction was the preferential formation of trans-but-2-ene, which is compatible with a reaction involving radical intermediates. Further evidence in support of a radical, rather than a carbonium ion, mechanism was obtained by observing the isomerization (a), in the presence of deuterium (when an enhancement of rate and extensive exchange were observed) and (b), in the presence of deuterium oxide (when very little exchange occurred and the reaction rate was fractionally reduced).Detailed analysis of the exchange products in the reaction of but-1-ene and deuterium over the NiX catalysts, where butane was a major product, suggested that all three butenes exchange at rates which are comparable to the rates of isomerization, and that the hydrogenation process involves a very substantial redistribution of H and D atoms between the molecules.
{"title":"Reactions of n-butene over a nickel exchanged 13X-type zeolite","authors":"N. E. Cross, C. Kemball, H. Leach","doi":"10.1039/J19710003315","DOIUrl":"https://doi.org/10.1039/J19710003315","url":null,"abstract":"The isomerization of n-butenes has been studied in a static system using as catalysts zeolites of the 13X-type with different extents of replacement of sodium ions by nickel ions. The presence of nickel enhances the catalytic activity considerably, comparable reaction rates with the nickel-containing zeolites being observed at temperatures 200 K lower than with the parent Na13X.A striking feature of the but-1-ene reaction was the preferential formation of trans-but-2-ene, which is compatible with a reaction involving radical intermediates. Further evidence in support of a radical, rather than a carbonium ion, mechanism was obtained by observing the isomerization (a), in the presence of deuterium (when an enhancement of rate and extensive exchange were observed) and (b), in the presence of deuterium oxide (when very little exchange occurred and the reaction rate was fractionally reduced).Detailed analysis of the exchange products in the reaction of but-1-ene and deuterium over the NiX catalysts, where butane was a major product, suggested that all three butenes exchange at rates which are comparable to the rates of isomerization, and that the hydrogenation process involves a very substantial redistribution of H and D atoms between the molecules.","PeriodicalId":17321,"journal":{"name":"Journal of The Chemical Society A: Inorganic, Physical, Theoretical","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91419556","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}
Silver carbonate prepared by precipitation from very dilute solutions of AgNO3 and NaHCO3 decomposes at 170 °C to yield Ag2O which is particularly active for the uptake of CO2. In contrast to other oxide adsorbents prepared from carbonates, the high activity is not a consequence of the development of a high surface area. The decomposition of Ag2CO3 leads to only a small increase in surface area, the oxide product having an area less than 1 m2 g–1. The activity in this system is linked instead with the presence of water. Co2 absorption depends upon the continuing availability of water at the reacting interface. Ag2O rapidly loses activity towards CO2 uptake in absorption–regeneration cycles if dry CO2 is employed. There is, in addition, a slow loss of activity during cycling which is independent of the presence of water. The results are discussed by use of a model in which water is considered to be incorporated in the oxide as OH– and in the carbonated solid as OH– and HCO3– ions.
{"title":"Reactivity of silver oxide in the absorption of carbon dioxide","authors":"P. A. Barnes, M. O'connor, F. Stone","doi":"10.1039/J19710003395","DOIUrl":"https://doi.org/10.1039/J19710003395","url":null,"abstract":"Silver carbonate prepared by precipitation from very dilute solutions of AgNO3 and NaHCO3 decomposes at 170 °C to yield Ag2O which is particularly active for the uptake of CO2. In contrast to other oxide adsorbents prepared from carbonates, the high activity is not a consequence of the development of a high surface area. The decomposition of Ag2CO3 leads to only a small increase in surface area, the oxide product having an area less than 1 m2 g–1. The activity in this system is linked instead with the presence of water. Co2 absorption depends upon the continuing availability of water at the reacting interface. Ag2O rapidly loses activity towards CO2 uptake in absorption–regeneration cycles if dry CO2 is employed. There is, in addition, a slow loss of activity during cycling which is independent of the presence of water. The results are discussed by use of a model in which water is considered to be incorporated in the oxide as OH– and in the carbonated solid as OH– and HCO3– ions.","PeriodicalId":17321,"journal":{"name":"Journal of The Chemical Society A: Inorganic, Physical, Theoretical","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91423643","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}
The crystal structure of µ-formato-diethylenetriaminecopper(II) formate has been determined by X-ray diffraction methods and refined by full-matrix least-squares procedure. Z= 4 in the orthorhombic unit cell, space group Pnam, with a= 8·954, b= 11·640, and c= 9·676 A. There are no discrete [Cu(dien)(HCO2)]+ ions in the crystal; chains of ions are formed parallel to a, the copper atoms being linked by formate groups in an anti–syn bridging arrangement. Each [Cu(dien)(HCO2)] group possesses mirror symmetry (space-group imposed) and the copper atom environment is essentially square-pyramidal. One oxygen atom co-ordinates to the copper atom at 2·035 A in the plane of the three equal copper–nitrogen bonds (2·012 A) and the apical position is occupied by a second oxygen atom 2·169 A from the copper atom.
{"title":"Structures of diethylenetriaminecopper(II) cations. Part IV. Crystal structure of µ-formato-diethylenetriaminecopper(II) formate","authors":"G. Davey, F. S. Stephens","doi":"10.1039/J19710000103","DOIUrl":"https://doi.org/10.1039/J19710000103","url":null,"abstract":"The crystal structure of µ-formato-diethylenetriaminecopper(II) formate has been determined by X-ray diffraction methods and refined by full-matrix least-squares procedure. Z= 4 in the orthorhombic unit cell, space group Pnam, with a= 8·954, b= 11·640, and c= 9·676 A. There are no discrete [Cu(dien)(HCO2)]+ ions in the crystal; chains of ions are formed parallel to a, the copper atoms being linked by formate groups in an anti–syn bridging arrangement. Each [Cu(dien)(HCO2)] group possesses mirror symmetry (space-group imposed) and the copper atom environment is essentially square-pyramidal. One oxygen atom co-ordinates to the copper atom at 2·035 A in the plane of the three equal copper–nitrogen bonds (2·012 A) and the apical position is occupied by a second oxygen atom 2·169 A from the copper atom.","PeriodicalId":17321,"journal":{"name":"Journal of The Chemical Society A: Inorganic, Physical, Theoretical","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79076696","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}
The effect of both ozoniser-type silent electric discharges and microwave discharges on silane, ammonia, and silane–ammonia mixtures is discussed. Silicon nitride films are formed in the microwave discharge of the latter.
{"title":"Effect of electrical discharge on silane and ammonia","authors":"J. Drake, N. Westwood","doi":"10.1039/J19710002587","DOIUrl":"https://doi.org/10.1039/J19710002587","url":null,"abstract":"The effect of both ozoniser-type silent electric discharges and microwave discharges on silane, ammonia, and silane–ammonia mixtures is discussed. Silicon nitride films are formed in the microwave discharge of the latter.","PeriodicalId":17321,"journal":{"name":"Journal of The Chemical Society A: Inorganic, Physical, Theoretical","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79105584","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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