Showing papers in "Canadian Journal of Chemistry in 1972"
TL;DR: In this article, the π-C6H6RuX2PR3 (X = Cl, Br, I, SCN) has been characterized, and the ε-C 6H6RX2RX 2PR3 has been obtained.
Abstract: The complexes [π-C6H6RuX2]2 (X = Cl, Br, I, SCN) have been prepared and characterized. They react with phosphorus donors to give the monomeric π-C6H6RuX2PR3, and with cyanide and hydride ions to gi...
360 citations
TL;DR: The rate constants for the abstraction of a hydrogen atom from a wide variety of organic substrates at 30° have been correlated with the strength of the C-H bond that are broken, D[R-H].
Abstract: The rate constants, kp, for the abstraction of a hydrogen atom from a wide variety of organic substrates at 30° have been correlated with the strengths of the C—H bond that are broken, D[R—H] (in u...
221 citations
TL;DR: Using an energy-resolved electron beam, appearance potentials for, and fragment ions from hydrocarbons of formula C 3H4, C3H6, C4H8, and C5H10 have been measured in this article.
Abstract: Using an energy-resolved electron beam, appearance potentials for,, and fragment ions from hydrocarbons of formula C3H4, C3H6, C4H6, C4H8, and C5H10 have been measured. In each case the fragment ap...
192 citations
TL;DR: Uracil was prepared enriched at C2 with carbon-13 and converted into uridine from which 2,5′-anhydro-1β-D-ribo-furanosyl and 2,2′]-anhydroid-1-β-d-arabino-furanusyl uracil were prepared as mentioned in this paper.
Abstract: Uracil was prepared enriched at C2 with carbon-13 and converted into uridine from which 2,5′-anhydro-1-β-D-ribo-furanosyl and 2,2′-anhydro-1-β-D-arabino-furanosyl uracil were prepared. The 13C2 to ...
157 citations
TL;DR: In this paper, the effect of changes in the relative orientation of vicinal and geminal 13C and 1H nuclei, and in the disposition of adjacent substituents, on coupling between these nuclei has been examined with a variety of 13C-labeled carbohydrates.
Abstract: The effect of changes in the relative orientation of vicinal and geminal 13C and 1H nuclei, and in the disposition of adjacent substituents, on coupling between these nuclei has been examined with a variety of 13C-labelled carbohydrates. Compounds synthesized for this purpose include derivatives of D-glucose-1- and -6-13C and L-idose-6-13C, and related lactones, and the measurements have been made with p.m.r. spectra of these compounds. Vicinal 13C-1H coupling, both through C—C and C—O bonds shows an orientational dependance analogous to that for protons: i.e., dihedral angles of 60–100° are associated with smaller coupling (0–3 Hz) than angles of 140–180° (4.5–5.5 Hz); sp2 carbon produces splittings of almost twice these values. The observed spacing is smaller when an oxygen atom is in the plane of the coupling pathway than when out of plane, both for vicinal and geminal 13C–1H interactions, and the presence of an extra oxygen also may have a notable impact on the geminal interaction. A study of rotation...
149 citations
TL;DR: In this paper, the adsorption of Co(II) by Fe3O4, Al2O3, and MnO2 has been studied as a function of the solution pH, solution-pH, and temperature.
Abstract: The adsorption of Co(II) by Fe3O4, Al2O3, and MnO2 has been studied as a function of Co(II) concentration, solution-pH, and temperature. It is observed that the adsorption of cobalt increases markedly with the solution pH between pH 5 and 7.5. Above pH 8 adsorption becomes increasingly masked by precipitation of Co(OH)2 and no resolution of these two contributions to the loss of Co(II) from solution is possible. A log θ/(1–θ) vs. pH plot is found to be linear between pH 5 and 7.5, where θ is the fraction of occupied adsorption sites. The presence of 0.1 m Ba2+ and Mg2+ in the solution does not seem to affect the hydrogen ion dependence of the adsorption of Co(II) on alumina.The adsorption results have been analyzed by the Langmuir adsorption isotherm over a wide range of Co(II) concentration (10−6–10−3 m). The adsorption of Co(II) is found to be an endothermic process and increases markedly with temperature between 30 and 100 °C. The heat of adsorption decreases with increasing surface coverage of the oxi...
141 citations
TL;DR: In this paper, the steric orientation of the reduction can be explained by the particular structure of potassium-graphite, and a new selective method of preparation of aldehydes from the corre sponding primary alcohol was proposed.
Abstract: Potassium in graphite shows distinctive reducing properties towards carbonyls The reaction products can be related to a mechanism similar to electrochemical reduction The steric orientation of the reduction can be explained by the particular structure of potassium–graphiteChromic anhydride in graphite offers a new selective method of preparation of aldehydes from the corre sponding primary alcohol This method is characterized by its specificity, high yields and a simple experimental procedure
128 citations
TL;DR: In this paper, the authors measured X-radiolysis free ion yields and electron mobilities in a series of branched chain hydrocarbons at several temperatures, including olefins and benzene.
Abstract: X-radiolysis free ion yields and electron mobilities were measured in a series of branched chain hydrocarbons at several temperatures. The numbers listed after the following compounds are the temperature (K), Gfi, most probable penetration range of the secondary electrons (A) and thermal electron mobility (cm2/V s): 2,2-dimethylpropane (neopentane), 294, 1.09, 213, 50; 2,2,3,3-tetramethylbutane, 379, 0.80, 130, –; 2,2,4,4-tetramethylpentane, 295, 0.83, 158, 24; 2,2,5,5-tetramethylhexane, 293, 0.67, 138, 12; 2,2,6,6-tetramethylheptane, 293, 0.47, 113, –; 2,2,7,7-tetramethyloctane, 383, 0.58, 100, –; 2,2,3,3-tetramethylpentane, 295, 0.42, 102, 5.2; cyclohexane, 294, 0.16, 67, 0.45. The difference between the activation energies of the reactionsandis (E15–E14) ≈ (2 to 3)RT for twenty two different hydrocarbons, including olefins and benzene. The rate of energy loss by epithermal electrons in liquid hydrocarbons increases with increasing anisotropy of polarizability of the molecules or groups; the range of th...
96 citations
TL;DR: Gran's functions corrected for buffering and H2O dissociation have been incorporated into the iterative calculation for the two equivalence points and the acid dissociation equilibria as discussed by the authors.
Abstract: Gran's functions corrected for buffering and H2O dissociation have been incorporated into the iterative calculation for the two equivalence points and the acid dissociation equilibria. The experime...
92 citations
TL;DR: In this paper, it was shown that antimonic acid cannot be dehydrated by heating in air to give products of constant and reproducible weight without simultaneous reduction of some of the SbV to SbIII.
Abstract: Antimonic acid cannot be dehydrated by heating in air to give products of constant and reproducible weight without simultaneous reduction of some of the SbV to SbIII. Neither anhydrous Sb2O5 nor th...
88 citations
TL;DR: Complexes of 2-pyridine thiol, 4-polycyclic pyridine and 2-methyl-6 pyridine thiol with cobalt(II), nickel, zinc, cadmium, mercury, platinum, and bismu... as discussed by the authors.
Abstract: Complexes of 2-pyridine thiol, 4-pyridine thiol, and 2-methyl-6-pyridine thiol, and some of their oxygen analogs with cobalt(II), nickel(II), zinc(II), cadmium(II), mercury(II), platinum(II), bismu...
TL;DR: A previously unknown alkaloid of molecular formula C15H20O2N2 was isolated from the dried root bark of EleagnusCommutata (Wolf willow or Silverberry) as discussed by the authors.
Abstract: A previously unknown alkaloid of molecular formula C15H20O2N2 was isolated from the dried root bark of EleagnusCommutata (Wolf willow or Silverberry). An X-ray analysis was undertaken to complete t...
TL;DR: The cubic pyrochlores Cd2Nb2O7, cd2Ta2O 7, Sn2Sb7O7 and Sn2Ta 2O7 were prepared and investigated by a number of methods.
Abstract: The cubic pyrochlores Cd2Nb2O7, Cd2Ta2O7, Sn2Nb2O7, Sn2Ta2O7. Cd2Sb7O7, Ca2Sb2O7, Mn2Sb2O7, Pb2Sb2O7, and related compounds were prepared and investigated by a number of methods. On heating above 7...
TL;DR: The minimum energy conformation of 2-methoxyethanol (CH3OCH2CH2OH) has been determined from an analysis of its microwave spectrum as discussed by the authors, which is one in which the hydroxyl hydrogen atom is approximately aligned with the nearest sp3 lone pair electrons of the ether oxygen atom.
Abstract: The minimum energy conformation of 2-methoxyethanol (CH3OCH2CH2OH) has been determined from an analysis of its microwave spectrum. The rotational constants of the normal species are: A = 12982.35, B = 2742.48, and C = 2468.10 MHz; the dipole moment components are μa = 2.03, μb = 1.15, and μ = 2.36 ± 0.03 D. For the CH3OCH2CH2OD species: A = 12385.71, B = 2724.74, and C = 2431.42 MHz. The conformation consistent with this data is gauche about each of the C—C, C—O(H) and C—O(ether) bonds, having dihedral angles of 57 ± 3°, 45 ± 5°, and 8 ± 3°, respectively. This distorted conformation is one in which the hydroxyl hydrogen atom is approximately aligned with the nearest sp3 lone pair electrons of the ether oxygen atom. Transitions in three excited torsional states have also been observed but no other rotational isomer was detected.
TL;DR: The X-ray crystal structure analysis of the triphenyl-phosphine platinum ethylene complex (PPh3)2PtC2H4 is reported in this article.
Abstract: The X-ray crystal structure analysis of the triphenyl–phosphine platinum ethylene complex (PPh3)2PtC2H4 is reported. The crystals belong to the monoclinic system a = 16.46(3), b = 10.85(2), c = 17....
TL;DR: MgV2O6 crystallizes in the monoclinic space group C2/m with lattice parameters a = 9.279(7), b = 3.502(2), c = 6.731(6)
Abstract: MgV2O6 crystallizes in the monoclinic space group C2/m with lattice parameters a = 9.279(7), b = 3.502(2), c = 6.731(6) A and β = 111.77(6)° with Z = 2. The structure was refined, at room temperatu...
TL;DR: In this article, the carbon-13 Fourier transform n.m. spectra of the biopolymer, heparin, are described, and the proton-decoupled spectrum corresponds to that of a molecular structure based on 12 carbon atoms.
Abstract: Carbon-13 Fourier transform n.m.r. spectra of the biopolymer, heparin, are described. The proton-decoupled spectrum corresponds to that of a molecular structure based on 12 carbon atoms, and the observed chemical shifts are shown to be consistent with a previously-proposed alternating sequence consisting of (1 → 4) linked residues of α-D-idopyranosyluronic acid 2-sulfate and 2-deoxy-2-sulfamino-α-D-glucopyranosyl 6-sulfate. Line-broadening of the C-6 signal of the latter residue indicates that spin–spin relaxation of the 13C nucleus of this sulfated primary carbinol group is more effective than for the 13C nuclei of the sugar rings. Among model compounds utilized for assignment of the signals from heparin is a disaccharide, 4-O-(α-L-idopyranosyluronic acid 2-sulfate)-2,5-anhydro-D-mannose 6-sulfate, prepared in 65% yield by deaminative degradation of heparin.
TL;DR: At room temperature Na4P2O7 crystallizes in the orthorhombic space group P212121 with a = 9.367(5), b = 5.390(2), c = 13.480(8)
Abstract: At room temperature Na4P2O7 crystallizes in the orthorhombic space group P212121 with a = 9.367(5), b = 5.390(2), c = 13.480(8) A, and z = 4. The structure was refined by full-matrix least-squares ...
TL;DR: The limiting high frequency permittivity e∞ of hexagonal ice, measured using a coaxial three terminal dielectric cell designed to minimize errors arising from differential thermal contraction, was described in this paper.
Abstract: The limiting high frequency permittivity e∞ of hexagonal ice, measured using a coaxial three terminal dielectric cell designed to minimize errors arising from differential thermal contraction, vari...
TL;DR: In this paper, the standard isothermal apparent molal compressibilities of tetraalkylammonium bromides in water at 25° were calculated from known standard apparentmolal adiabatic compressibilities, expansitivites, and heat capacities.
Abstract: The standard isothermal apparent molal compressibilities, of tetraalkylammonium bromides in water at 25° were calculated from known standard apparent molal adiabatic compressibilities, expansitivites, and heat capacities, is significantly different from and depends mostly on the extrapolation procedure used to obtain and on the precision of
TL;DR: In this paper, H2S adaption and subsequent reaction on alumina gave major I.r. bands at 1341, 1568, 1625, and 3400 cm−1.
Abstract: Adsorption and subsequent reaction of H2S on alumina gave major i.r. bands at 1341, 1568, 1625, and 3400 cm−1. Relative band intensities were used to follow the first order decomposition of adsorbe...
TL;DR: The photolysis of 1,4-benzoquinone, duroquinone and 1, 4-naphthoquinone in isopropanol and in dioxane leads to the observation of e.s.r.
Abstract: The photolysis of 1,4-benzoquinone, duroquinone, and 1,4-naphthoquinone in isopropanol and in dioxane leads to the observation of e.s.r. spectra of the corresponding semiquinone radicals. The rates...
TL;DR: In this article, the apparent molal volumes and heat capacities of quaternary ions were measured in water and methanol at 25 °C in the concentration range 0.01-0.2
Abstract: The apparent molal volumes and heat capacities of Bu4NBr, NaBPh4, Ph4PCl, and Ph4AsCl have been measured in water and methanol at 25 °C in the concentration range 0.01–0.2 M. The viscosity of aqueous NaBPh4 and Ph4AsCl have also been measured at 25 °C and in the same concentration range. Individual ionic values have been estimated for most of these properties. A comparison of these values for the quaternary ions BU4N+, , Ph4P+, Ph4As+ illustrates sizable differences in the solute–solvent interactions of alkyl and aryl substituted ions. Some specificity is also suggested in the solvation of the tetraphenyl ions, as shown by a comparison of the properties which should reflect directly the size of the ions and also in (H2O → CH3OH) transfer functions.
TL;DR: In this article, a combination of X-ray intensity data and the chain packing analyses have shown that the overall number of permissible structures is very limited so that van der Waals' forces play a major role in packing.
Abstract: The crystallographic structure of mannan I has been examined by X-ray fiber diffraction, polarized i.r. spectroscopy, and computer chain-packing methods. The combination of X-ray intensity data and the chain packing analyses have shown that the overall number of permissible structures is very limited so that van der Waals' forces play a major role in packing. It was concluded that the chain senses are anti-parallel. The interpretation of the polarized i.r. spectra in the OH stretching region is in line with the presence of an intra-molecular hydrogen-bond between O(3)… O(5′). The awkward "knobby" shape of the mannan molecule, largely a result of the axial disposition of O(2)—H, lends itself to a close packing mainly determined by van der Waals' forces. The considerable similarity between X-ray and i.r. data from mannans and glucomannans would indicate that structural conclusions about the former might relate to the latter.
TL;DR: In this paper, the results of extensive infrared absorption measurements of CH4, CD4, and mixed isotopic crystals containing CH 4, CD 4, CHD3, and CH3D at low concentration in matrices of light were reported.
Abstract: This paper reports the results of extensive infrared absorption measurements of CH4, CD4, and mixed isotopic crystals containing CH4, CD4, CHD3, and CH3D at low concentration in matrices of light a...
TL;DR: In this article, the preparation of hydroxy bridged complexes, [M2(OH)2L4][BF4]2, where M = pt and L = triethylphosphine, triphenylphosphines, or pyridine, is described.
Abstract: The preparation of hydroxy bridged complexes, [M2(OH)2L4][BF4]2, where M = Pt and L = triethylphosphine, triphenylphosphine or pyridine, or where M = Pd and L = triphenylphosphine, is described. The structures are unambiguously established by infrared, nuclear magnetic resonance, and X-ray crystallographic studies. The complexes are surprisingly stable, and in particular, resist bridge cleavage by tertiary phosphines under conditions which easily cleave analogous chloro bridged complexes.
TL;DR: In this article, the diffusion coefficients in air at 298.2 °K and 1 atm pressure were reported for different types of butane, ethene, ethane, cyclopropane, propene, propadiene and propyne.
Abstract: Diffusion coefficients in air at 298.2 °K and 1 atm pressure are reported for ethane, ethene, ethyne, cyclopropane, propene, propadiene, propyne, butane, 1-butene, 2-methylpropene, cis-2-butene, tr...
TL;DR: In this article, the Fermi contact contribution to three-bond carbon-proton coupling constants in propane was calculated at the INDO level of approximation using molecular orbital theory.
Abstract: Molecular orbital theory at the INDO level of approximation is used to calculate the Fermi contact contribution to three-bond carbon–proton coupling constants in propane. The calculations predict a dihedral angle dependence of 3J(13C,H) in the 13C—C—C—H fragment similar to that observed for 3J(H,H), 3J(19F,H), and for 3J(31P,H) in the saturated X—C—C—H fragments.
TL;DR: In this paper, the carbon-13 n.m. spectra of 26 α,β-unsaturated methyl esters and 16 substituted acrylic acids have been determined and the 13C shieldings are discussed.
Abstract: The carbon-13 n.m.r. spectra of 26 α,β-unsaturated methyl esters and 16 substituted acrylic acids have been determined and the 13C shieldings are discussed. These data are compared with the recently reported values for several α,β-unsaturated carboxylic acids. Linear regression analysis of the olefinic shielding data for several α,β-unsaturated carbonyl derivatives yields a set of parameters which correlate the results with reasonable precision. The solvent dependence of the 13C shieldings of acrylic acid and methyl acrylate has been examined briefly. The proton results for the methyl esters are discussed briefly.
TL;DR: In this article, the co-condensation reaction of atomic palladium with a dilute CO-argon mixture (1:1000) at 10°K yields intermediate carbonyls of palladium Pd(CO)n where n = 1−3 as well as very small amounts of PdCO)4.
Abstract: The co-condensation reaction of atomic palladium with a dilute CO–argon mixture (1:1000) at 10°K yields intermediate carbonyls of palladium Pd(CO)n where n = 1–3 as well as very small amounts of Pd(CO)4. Isotopic substitution experiments using 12C18O were used to aid the spectral assignments. The probabilities of forming the various Pd(CO)n carbonyl species as a function of the CO concentration in Ar are analyzed and compared with the experimental observations. An analysis of the diffusion kinetics demonstrates their usefulness in assigning bands to various species in a series of compounds such as Pd(CO)n. The data make possible the assignment of infrared absorptions at 2070, 2060, 2044, and 2050 cm-1 to tetrahedral (Td) Pd(CO)4, trigonal planar (D3h) Pd(CO)3, linear (D8h) Pd(CO)2 and linear (C8v) PdCO, respectively. Cotton–Kraihanzel force constants are calculated for Pd(CO)n and are compared with those for the analogous intermediate carbonyls of nickel, Ni(CO)n.