The structure of tetra-n-butylammonium iodopentadecacarbonylhexarhodate [N(C4H9)4][Rh6(CO)15l] has been determined from three-dimensional X-ray data collected by counter methods. The crystals are monoclinic with a= 14·93(2), b= 20·02(3), c= 15·50(2)A, β= 111·0(1)°, space group P21/n, and Z= 4. The structure determination, based on 1650 independent reflections, has been refined to R= 0·041. The crystal contains cluster anions [Rh6(CO)15l]– closely related to Rh6(CO)16. The mean edge of the metal octahedron is 2·746 A long. Each of four carbonyl groups bridges three metal atoms on alternate faces of the octahedron and the remaining carbonyl groups and the iodine atom behave as unidentate ligands. The Rh–l distance is 2·709(6)A. The idealized symmetry of the anion is Cs.
{"title":"Crystal and molecular structure of the tetra-n-butylammonium salt of the cluster anion iodopentadecacarbonylhexarhodate","authors":"V. Albano, P. L. Bellon, M. Sansoni","doi":"10.1039/J19710000678","DOIUrl":"https://doi.org/10.1039/J19710000678","url":null,"abstract":"The structure of tetra-n-butylammonium iodopentadecacarbonylhexarhodate [N(C4H9)4][Rh6(CO)15l] has been determined from three-dimensional X-ray data collected by counter methods. The crystals are monoclinic with a= 14·93(2), b= 20·02(3), c= 15·50(2)A, β= 111·0(1)°, space group P21/n, and Z= 4. The structure determination, based on 1650 independent reflections, has been refined to R= 0·041. The crystal contains cluster anions [Rh6(CO)15l]– closely related to Rh6(CO)16. The mean edge of the metal octahedron is 2·746 A long. Each of four carbonyl groups bridges three metal atoms on alternate faces of the octahedron and the remaining carbonyl groups and the iodine atom behave as unidentate ligands. The Rh–l distance is 2·709(6)A. The idealized symmetry of the anion is Cs.","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":"79186328","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}
Cyclohexene, cyclohexa-1,3-diene, and cyclohexa-1,4-diene react rapidly with palladium acetate in acetic acid solution to yield benzene. The reaction has a heterogeneous catalytic step since it depends on palladium metal formed in the system. The metal is slightly hydrided and is a very efficient disproportionation catalyst. Both HClO4 and NaOAc promote oxidation at the expense of disproportionation. Similar oxidations of cyclohexanone or hydroxy-cyclohexenes give phenol while acetoxy-cyclohexenes yield mixtures of phenyl acetate and benzene. In 0·5M-HClO4 there is a competing very fast oxidation that yields cyclohexanone, cyclohex-1-en-1-yl acetate, and cyclohex-3-en-1-yl acetate from cyclohexene. In the presence of oxygen, cyclohexene undergoes a slow palladdium acetate-catalysed homogeneous oxidation to yield cyclohex-2-en-1-yl acetate. A concurrent free-radical process yields cyclohex-2-en-1-ol and cyclohex-2-en-1-one. Cyclohexa-1,3-diene is oxidised rapidly by oxygen in the presence of Pd(OAc)2 giving a complex mixture of products, the main one being cyclohex-2-ene-1,4-diol diacetate. Under similar homogeneous conditions, cyclohexa-1,4-diene gives benzene, cyclohex-4-ene-1,3-diol diacetate, and Pd2(C6H8)(OAc)2 as a by-product. The palladium acetate-catalysed oxidation of cyclohexene, cyclohexa-1,3-diene, and cyclohexa-1,4-diene by benzoquinone yields cyclohex-2-en-1-yl acetate, cyclohex-2-ene-1,4-diol diacetate, and cyclohex-4-ene-1,3-diol diacetate respectively with benzene, also, from cyclohexa-1,4-diene. The roles of oxypalladation adducts and π-cyclohexenylpalladium complexes in these reactions are discussed.
环己烯、环己-1,3-二烯和环己-1,4-二烯在乙酸溶液中与醋酸钯快速反应生成苯。该反应具有非均相催化步骤，因为它依赖于系统中形成的钯金属。金属微氢化，是一种非常有效的歧化催化剂。HClO4和NaOAc都以歧化为代价促进氧化。环己酮或羟基环己烯类似的氧化反应生成苯酚，而乙酰氧基环己烯则生成乙酸苯和苯的混合物。在0.5 m - hclo4中，环己烯发生竞争性的快速氧化反应，生成环己酮、乙酸环己烯-1-烯-1-酯和乙酸环己烯-3-烯-1-酯。在氧的存在下，环己烯经历缓慢的醋酸钯催化均相氧化生成环己烯-2-烯-1-乙酸酯。同时自由基反应生成环己烯-2-烯-1-醇和环己烯-2-烯-1- 1。环己-1,3-二烯在Pd(OAc)2的存在下被氧迅速氧化，生成复杂的混合物，主要产物是环己-2-烯-1,4-二醇二乙酸酯。在相似的均相条件下，环己-1,4-二烯生成苯、环己-4-烯-1,3-二醇二乙酸酯和副产物Pd2(C6H8)(OAc)2。用苯醌催化醋酸钯氧化环己烯、环己-1,3-二烯和环己-1,4-二烯，分别得到环己-2-烯-1-乙酸酯、环己-2-烯-1,4-二醇二乙酸酯和环己-4-烯-1,3-二醇二乙酸酯。讨论了氧化加合物和π-环己烯钯配合物在这些反应中的作用。
{"title":"Reaction of metal-ion complexes with hydrocarbons. Part III. Palladium acetate in the oxidation and autoxidation reactions of cyclohexene, cyclohexa-1,3-diene, and cyclohexa-1,4-diene in acetic acid solution","authors":"R. G. Brown, J. M. Davidson","doi":"10.1039/J19710001321","DOIUrl":"https://doi.org/10.1039/J19710001321","url":null,"abstract":"Cyclohexene, cyclohexa-1,3-diene, and cyclohexa-1,4-diene react rapidly with palladium acetate in acetic acid solution to yield benzene. The reaction has a heterogeneous catalytic step since it depends on palladium metal formed in the system. The metal is slightly hydrided and is a very efficient disproportionation catalyst. Both HClO4 and NaOAc promote oxidation at the expense of disproportionation. Similar oxidations of cyclohexanone or hydroxy-cyclohexenes give phenol while acetoxy-cyclohexenes yield mixtures of phenyl acetate and benzene. In 0·5M-HClO4 there is a competing very fast oxidation that yields cyclohexanone, cyclohex-1-en-1-yl acetate, and cyclohex-3-en-1-yl acetate from cyclohexene. In the presence of oxygen, cyclohexene undergoes a slow palladdium acetate-catalysed homogeneous oxidation to yield cyclohex-2-en-1-yl acetate. A concurrent free-radical process yields cyclohex-2-en-1-ol and cyclohex-2-en-1-one. Cyclohexa-1,3-diene is oxidised rapidly by oxygen in the presence of Pd(OAc)2 giving a complex mixture of products, the main one being cyclohex-2-ene-1,4-diol diacetate. Under similar homogeneous conditions, cyclohexa-1,4-diene gives benzene, cyclohex-4-ene-1,3-diol diacetate, and Pd2(C6H8)(OAc)2 as a by-product. The palladium acetate-catalysed oxidation of cyclohexene, cyclohexa-1,3-diene, and cyclohexa-1,4-diene by benzoquinone yields cyclohex-2-en-1-yl acetate, cyclohex-2-ene-1,4-diol diacetate, and cyclohex-4-ene-1,3-diol diacetate respectively with benzene, also, from cyclohexa-1,4-diene. The roles of oxypalladation adducts and π-cyclohexenylpalladium complexes in these reactions are discussed.","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":"79705204","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 transformations brushite → fluoroapatite and monetite → fluoroapatite have been investigated at 25 °C in aqueous acidic KF solutions, ca. 10–1M in F–. The transformations involve a first-order uptake of F– by the secondary orthophosphates, followed by a solid-state rearrangement to fluoroapatite with the second-order release of H2PO4–. The ΔGf° for fluoroapatite has been calculated from the brushite → apatite transformation as –1524·1 kcal mol–1, and confirmed by calculation of the ΔGf° value for monetite as –401·1 kcal mol–1. From these results, the ΔGf° values of hydroxyapatite, Ca5OH(PO4)2, Ca3(PO4)2, and Ca(H2PO4)2, and Ca(H2PO4)2,H2O were calculated as –1494·2, –925·1, –677·8, and –729·5 kcal mol–1. The possibility of K substitution for Ca in fluoroapatite is discussed.
{"title":"Orthophosphates. Part II. The transformations brushite → fluoroapatite and monetite → fluoroapatite in aqueous potassium fluoride solution","authors":"E. J. Duff","doi":"10.1039/J19710000033","DOIUrl":"https://doi.org/10.1039/J19710000033","url":null,"abstract":"The transformations brushite → fluoroapatite and monetite → fluoroapatite have been investigated at 25 °C in aqueous acidic KF solutions, ca. 10–1M in F–. The transformations involve a first-order uptake of F– by the secondary orthophosphates, followed by a solid-state rearrangement to fluoroapatite with the second-order release of H2PO4–. The ΔGf° for fluoroapatite has been calculated from the brushite → apatite transformation as –1524·1 kcal mol–1, and confirmed by calculation of the ΔGf° value for monetite as –401·1 kcal mol–1. From these results, the ΔGf° values of hydroxyapatite, Ca5OH(PO4)2, Ca3(PO4)2, and Ca(H2PO4)2, and Ca(H2PO4)2,H2O were calculated as –1494·2, –925·1, –677·8, and –729·5 kcal mol–1. The possibility of K substitution for Ca in fluoroapatite is discussed.","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":"83260955","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}
M. Lappert, M. Litzow, J. Pedley, T. Spalding, H. Nöth
Redistribution equilibria: ⅔BX3+⅓BY3⇌ BX2Y and ⅓BX3+⅔BY3⇌ BXY2 among all the boron trihalides have been examined by 11B n.m.r. spectroscopy in solvents methylcyclohexane and 1,1-dichloroethane at 33·5 °C; variable temperature studies have been completed for the BCl3–BBr3 systems. Entropy changes were also calculated from spectroscopic data and show tittle deviation from calculations based on symmetry factors alone. The reactions depart only slightly from thermoneutrality (<2 kcal mol–1) and endothermicity appears to increase with increasing disparity between the electronegativities of X and Y. There is no detectable solvent effect in the two media examined and, insofar as comparison permits, no significant deviation from the situation in the gas phase.
{"title":"Bonding studies of compounds of boron and the group IV elements. Part IV. Redistribution equilibria among the boron trihalides by 11B nuclear resonance","authors":"M. Lappert, M. Litzow, J. Pedley, T. Spalding, H. Nöth","doi":"10.1039/J19710000383","DOIUrl":"https://doi.org/10.1039/J19710000383","url":null,"abstract":"Redistribution equilibria: ⅔BX3+⅓BY3⇌ BX2Y and ⅓BX3+⅔BY3⇌ BXY2 among all the boron trihalides have been examined by 11B n.m.r. spectroscopy in solvents methylcyclohexane and 1,1-dichloroethane at 33·5 °C; variable temperature studies have been completed for the BCl3–BBr3 systems. Entropy changes were also calculated from spectroscopic data and show tittle deviation from calculations based on symmetry factors alone. The reactions depart only slightly from thermoneutrality (<2 kcal mol–1) and endothermicity appears to increase with increasing disparity between the electronegativities of X and Y. There is no detectable solvent effect in the two media examined and, insofar as comparison permits, no significant deviation from the situation in the gas phase.","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":"83419076","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}
Newberryite, MgHPO4,3H2O, was transformed in aqueous solutions of NaOH into bobierrite, Mg3(PO4)2,8H2O. A competing transformation in a solution which was 10–1M in both NaOH and NaF is the formation of magnesium fluoroapatite Mg5F(PO4)3. The nature of the reactions are discussed and ΔG°f values for Mg3(PO4)3,8H2O. MgHPO4,3H2O, Mg5F(PO4)3, Mg5OH(PO4)3, Mg(H2PO4)2, Mg(H2PO4)2,2H2O, Mg(H2PO4)2,4H2O, Mg4O(PO4)2, and Mg2F(PO4)2 have been calculated as –1302·7, –549·0, –1399·2. –1376·2, –652·5, –764·9, –878·2, –997·3 and –551·0 kcal mol–1 respectively. The nature of the stability relationships existing between the orthophosphate phases has been determined.
{"title":"Orthophosphates. Part VIII. The transformation of newberryite into bobierrite in aqueous alkaline solutions","authors":"E. J. Duff","doi":"10.1039/J19710002736","DOIUrl":"https://doi.org/10.1039/J19710002736","url":null,"abstract":"Newberryite, MgHPO4,3H2O, was transformed in aqueous solutions of NaOH into bobierrite, Mg3(PO4)2,8H2O. A competing transformation in a solution which was 10–1M in both NaOH and NaF is the formation of magnesium fluoroapatite Mg5F(PO4)3. The nature of the reactions are discussed and ΔG°f values for Mg3(PO4)3,8H2O. MgHPO4,3H2O, Mg5F(PO4)3, Mg5OH(PO4)3, Mg(H2PO4)2, Mg(H2PO4)2,2H2O, Mg(H2PO4)2,4H2O, Mg4O(PO4)2, and Mg2F(PO4)2 have been calculated as –1302·7, –549·0, –1399·2. –1376·2, –652·5, –764·9, –878·2, –997·3 and –551·0 kcal mol–1 respectively. The nature of the stability relationships existing between the orthophosphate phases has been determined.","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":"83419724","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 the olefin complex, [PtCl3(C4H12N2)]+, of platinum(II) with the trans-but-2-en-1,4-diammonium cationic ligand, has been determined as its hemihydrate chloride salt, by single-crystal X-ray methods. The compound [PtCl3(C4H12N2)]Cl,½H2O forms yellow monoclinic crystals, a= 23·911, b= 6·942, c= 13·586 A, β= 102·07°, space group C2/c with Z= 8. The structure, solved by standard methods, has been refined anisotropically by full-matrix least-squares methods to R 0·037, by use of 2447 independent reflections collected by counter methods.The structure contains discrete ions linked into infinite two-dimensional layers by chains of O–H ⋯ Cl, N–H ⋯ O, N–H ⋯ Cl hydrogen bonds. In the cation, platinum is four-co-ordinate with the three chlorine atoms and the double bond of the unsaturated diammonium cationic ligand. The structure of the complex is discussed together with the changes in the olefin caused by co-ordination. Comparison with similar platinum(II)–olefin complexes is made.
{"title":"Crystal and molecular structure of trichloro(π-trans-but-2-en-1,4-diammonium)platinum(II) chloride","authors":"R. Spagna, L. Zambonelli","doi":"10.1039/J19710002544","DOIUrl":"https://doi.org/10.1039/J19710002544","url":null,"abstract":"The structure of the olefin complex, [PtCl3(C4H12N2)]+, of platinum(II) with the trans-but-2-en-1,4-diammonium cationic ligand, has been determined as its hemihydrate chloride salt, by single-crystal X-ray methods. The compound [PtCl3(C4H12N2)]Cl,½H2O forms yellow monoclinic crystals, a= 23·911, b= 6·942, c= 13·586 A, β= 102·07°, space group C2/c with Z= 8. The structure, solved by standard methods, has been refined anisotropically by full-matrix least-squares methods to R 0·037, by use of 2447 independent reflections collected by counter methods.The structure contains discrete ions linked into infinite two-dimensional layers by chains of O–H ⋯ Cl, N–H ⋯ O, N–H ⋯ Cl hydrogen bonds. In the cation, platinum is four-co-ordinate with the three chlorine atoms and the double bond of the unsaturated diammonium cationic ligand. The structure of the complex is discussed together with the changes in the olefin caused by co-ordination. Comparison with similar platinum(II)–olefin complexes is made.","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":"83448673","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}
Exposure of aqueous solutions of alkali-metal bromides or iodides to 60Co γ-rays at 77 K gave hydroxyl radicals, Br2– or I2–, and species identified as BrOH– or IOH–. The resulting magnetic parameters are compared with those for VK centres in alkali halide crystals, and with CIOH– in strontium chloride hexahydrate. Argentic and mercuric iodide complexes in frozen aqueous solution gave only I2– under these conditions.
{"title":"Unstable intermediates. Part LXXXII. Electron spin resonance spectra of the species Br2–, I2–, BrOH–, and IOH– in γ-irradiated frozen aqueous solutions of alkali-metal halides","authors":"I. Marov, M. Symons","doi":"10.1039/J19710000201","DOIUrl":"https://doi.org/10.1039/J19710000201","url":null,"abstract":"Exposure of aqueous solutions of alkali-metal bromides or iodides to 60Co γ-rays at 77 K gave hydroxyl radicals, Br2– or I2–, and species identified as BrOH– or IOH–. The resulting magnetic parameters are compared with those for VK centres in alkali halide crystals, and with CIOH– in strontium chloride hexahydrate. Argentic and mercuric iodide complexes in frozen aqueous solution gave only I2– under these conditions.","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":"83455729","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 the hydrides of Group V and VI are investigated with a single-centre molecular orbital model. This model in the form of empirical United Atom correlation diagrams is appropriate to the description of ligand molecules because it predicts with little difficulty the symmetries and energies of the ligand frontier orbitals. The necessary second-order perturbations are discussed in terms of three effects, the Off-Centre-Atom (OCA) field, configuration interaction and the Anisotropic Potential Destablization (APD). The Lewis basicity of the highest occupied ligand orbital is described in terms of the orbital symmetry, localization, and the extent of the APD effect. The chemical behaviour predicted with these spectroscopic criteria is consistant with the observed co-ordinating ability of these ligands.
{"title":"United atom models for polyatomic ligands. Part I. Hydrogen derivatives","authors":"B. Hollebone","doi":"10.1039/J19710003008","DOIUrl":"https://doi.org/10.1039/J19710003008","url":null,"abstract":"The electronic structures of the hydrides of Group V and VI are investigated with a single-centre molecular orbital model. This model in the form of empirical United Atom correlation diagrams is appropriate to the description of ligand molecules because it predicts with little difficulty the symmetries and energies of the ligand frontier orbitals. The necessary second-order perturbations are discussed in terms of three effects, the Off-Centre-Atom (OCA) field, configuration interaction and the Anisotropic Potential Destablization (APD). The Lewis basicity of the highest occupied ligand orbital is described in terms of the orbital symmetry, localization, and the extent of the APD effect. The chemical behaviour predicted with these spectroscopic criteria is consistant with the observed co-ordinating ability of these ligands.","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":"87316875","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}
Vertical ionization potentials, calculated as the difference between the total energies of the ground states of the ion and its parent molecule, are compared with estimates obtained by use of Koopmans' theorem. For some molecules the differences between the two theoretical values are quite large, while for molecules where the molecular orbitals are constrained by symmetry, the two theoretical values are identical. Differences between calculated adiabatic and vertical ionization potentials are shown to agree with the qualitative features of photoelectron spectra. The best overall fit of theoretical and experimental ionization potentials is obtained with atomic parameters evaluated from Hinze and Jaffe valence-state data and resonance integrals dependent upon valence-state ionization potentials. The theoretical predictions are generally superior to those of CNDO/2 or Hartree–Fock calculations.
{"title":"An SCF–MO–CNDO study of ionization potentials and orbital energies by the CNDO/BW theory","authors":"R. J. Boyd, M. Whitehead","doi":"10.1039/J19710003579","DOIUrl":"https://doi.org/10.1039/J19710003579","url":null,"abstract":"Vertical ionization potentials, calculated as the difference between the total energies of the ground states of the ion and its parent molecule, are compared with estimates obtained by use of Koopmans' theorem. For some molecules the differences between the two theoretical values are quite large, while for molecules where the molecular orbitals are constrained by symmetry, the two theoretical values are identical. Differences between calculated adiabatic and vertical ionization potentials are shown to agree with the qualitative features of photoelectron spectra. The best overall fit of theoretical and experimental ionization potentials is obtained with atomic parameters evaluated from Hinze and Jaffe valence-state data and resonance integrals dependent upon valence-state ionization potentials. The theoretical predictions are generally superior to those of CNDO/2 or Hartree–Fock calculations.","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":"80680461","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}
Hexacyanoferric(II) acid readily absorbs boron trifluoride (but not boron trichloride) to form the adduct Fe(CNH)4(CN)2,2BF3. The trans-dicyanotetrakis(alkyl isocyanide)iron(II) complexes Fe(CNMe)4(CN)2 and Fe(CNEt)4(CN)2 readily absorb either of these boron trihalides to form adducts Fe(CNR)4(CN)2,2BX3. The i.r. and Mossbauer spectra of these adducts are interpreted in terms of structures Fe(CNR)4(CN,BX3)2 with the Lewis acids linked to the nitrogen atoms of the cyanide group. The spectra are consistent with local octahedral symmetry at iron, indicating the similar π-acid ligand properties of the groups CNR and CNBX3, although in the cyanide stretching region the two i.r. bands appropriate for D4h symmetry are observed.
{"title":"Adducts of hexacyanoferric(II) acid, trans-dicyanotetrakis(methyl isocyanide)iron(II), and trans-dicyanotetrakis(ethyl isocyanide)iron(II) with boron trihalides. Infrared and Mössbauer spectroscopic studies","authors":"D. Hall, J. Slater, B. Fitzsimmons, K. Wade","doi":"10.1039/J19710000800","DOIUrl":"https://doi.org/10.1039/J19710000800","url":null,"abstract":"Hexacyanoferric(II) acid readily absorbs boron trifluoride (but not boron trichloride) to form the adduct Fe(CNH)4(CN)2,2BF3. The trans-dicyanotetrakis(alkyl isocyanide)iron(II) complexes Fe(CNMe)4(CN)2 and Fe(CNEt)4(CN)2 readily absorb either of these boron trihalides to form adducts Fe(CNR)4(CN)2,2BX3. The i.r. and Mossbauer spectra of these adducts are interpreted in terms of structures Fe(CNR)4(CN,BX3)2 with the Lewis acids linked to the nitrogen atoms of the cyanide group. The spectra are consistent with local octahedral symmetry at iron, indicating the similar π-acid ligand properties of the groups CNR and CNBX3, although in the cyanide stretching region the two i.r. bands appropriate for D4h symmetry are observed.","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":"85272683","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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