Showing papers in "Canadian Journal of Chemistry in 1985"
TL;DR: In this article, a simple model based on electrostatic interaction between the monomers was proposed to predict Van der Waals complexes, and point multipoles were assigned to the atoms and embedded in hard sphere.
Abstract: Structures of Van der Waals complexes are predicted by a simple model based on electrostatic interaction between the monomers. Point multipoles are assigned to the atoms and embedded in hard sphere...
499 citations
TL;DR: In this article, the authors derived expressions from which stretching force constants for the weak bond in weakly bound dimers may be evaluated directly from observed rotational constants and centrifugal stretching distor...
Abstract: Expressions are derived from which stretching force constants for the weak bond in weakly bound dimers may be evaluated directly from observed rotational constants and centrifugal stretching distor...
425 citations
TL;DR: In a dispersion polymerization process, the reaction mixture starts out as a homogeneous solution and the resulting polymer precipitates as spherical particles, stabilized by a steric barrier of di....
Abstract: In a dispersion polymerization process, the reaction mixture starts out as a homogeneous solution and the resulting polymer precipitates as spherical particles, stabilized by a steric barrier of di...
314 citations
TL;DR: In this article, a variety of dipole oscillator strength distributions have been constructed, and used to evaluate integrated DOW oscillator strengths and various DOW strength properties, for ground state ground state applications.
Abstract: Dipole oscillator strength distributions have been constructed, and used to evaluate integrated dipole oscillator strengths and a variety of dipole oscillator strength properties, for ground state ...
157 citations
TL;DR: In this article, metal-free, copper, cobalt(II), and zinc 2,9,16,23-tetraalkoxyphthalocyanines, some of which are extremely soluble in organic solvents, are described.
Abstract: Metal-free copper and cobalt(II) binuclear phthalocyanines, in which the two phthalocyanine nuclci are covalently linked through five-atom bridges, have been prepared and characterized. Some new metal-free, copper, cobalt(II), and zinc 2,9,16,23-tetraalkoxyphthalocyanines, some of which are extremely soluble in organic solvents, are described.
150 citations
TL;DR: In this paper, the two phthalocyanine nuclei are covalently linked through four-atom bridges, derived from catechol, and a metal-free 2,9,16,23-t
Abstract: Binuclear phthalocyanines in which the two phthalocyanine nuclei are covalently linked through four-atom bridges, derived from catechol, have been prepared and characterized. Metal-free 2,9,16,23-t...
132 citations
TL;DR: In this paper, it was shown that titanium dioxide does in fact photogenerate H2O2 in the presence of the donor sodium formate, however, this H 2O2 has only a transient existence in aque...
Abstract: Evidence is presented which demonstrates that titanium dioxide does in fact photogenerate H2O2 in the presence of the donor sodium formate. However, this H2O2 has only a transient existence in aque...
128 citations
TL;DR: Quantitative studies of the effect of the inhibitors ascorbic acid, α-tocopherol, and 6-hydroxy-2,5,7,8-tetramethyl-chroman-2-carboxylate on the autoxidation of linoleic acid in micellar DBHN micelles reveal that C functions to regenerate a mole of E (or T) per mole of C used.
Abstract: A study was made of the effect of the inhibitors ascorbic acid (C), α-tocopherol (E), and 6-hydroxy-2,5,7,8-tetramethyl-chroman-2-carboxylate (Trolox, T) on the autoxidation of linoleic acid in 0.5...
105 citations
TL;DR: In this paper, a new family of high-quality Gaussian-type function basis sets capable of producing near Hartree-Fock atomic and molecular wave functions has been proposed.
Abstract: We have started to prepare a new family of high-quality Gaussian-type function basis sets capable of producing near Hartree–Fock atomic and molecular wave functions. A conspicuous feature of the fa...
100 citations
TL;DR: Amines were reacted with lactones 7 or with unsaturated nitro derivatives 8 to give isoindole and pyrazino[2,1-a]isoindole derivatives as mentioned in this paper.
Abstract: Amines were reacted with lactones 7 or with unsaturated nitro derivatives 8 to give isoindole and pyrazino[2,1-a]isoindole derivatives. The mechanisms of formation, proofs of structure, and stereoc...
96 citations
TL;DR: The fluorescence of 6-aminocoumarine (A6C) is very weak and anomalously redshifted as compared to its 7-substituted analogues 4-methyl-7-amina (A7C) and 4-methylaminocoumarines (D) as mentioned in this paper.
Abstract: The fluorescence of 6-aminocoumarine (A6C) is very weak and anomalously redshifted as compared to its 7-substituted analogues 4-methyl-7-aminocoumarine (A7C) and 4-methyl-7-diethylaminocoumarine (D
TL;DR: The preparative value of the 1-(phenylsulfonyl) N-blocking and directing group for the synthesis of 3-acylpyrroles has been further evaluated in this article.
Abstract: The preparative value of the 1-(phenylsulfonyl) N-blocking and directing group for the synthesis of 3-acylpyrroles has been further evaluated. Acetylation and benzoylation are strongly regiospecifi...
TL;DR: The crystal structures of cellulose polymorphs IVI and IVII have been determined by X-ray fiber diffraction analysis combined with stereochemical model refinement as discussed by the authors, and both structures crystallize in a...
Abstract: The crystal structures of cellulose polymorphs IVI and IVII have been determined by X-ray fiber diffraction analysis combined with stereochemical model refinement. Both structures crystallize in a ...
TL;DR: The pKa's of 13 heterocyclic aromatic compounds have been measured in tetrahydrofuran (THF) using 13C nmr spectroscopy as discussed by the authors.
Abstract: The pKa's of 13 heterocyclic aromatic compounds have been measured in tetrahydrofuran (THF) using 13C nmr spectroscopy. The acidifying effect of a nitrogen heteroatom is seen to be quite large (4–6...
TL;DR: In this article, it was shown that the tert-butyloxycarbonylation of phenols, alcohols, enols, and thiols can be accomplished by reaction of these functionalities with di-tertbutyl dicarbonate under phase transfer.
Abstract: It is shown that the tert-butyloxycarbonylation of phenols, alcohols, enols, and thiols can be accomplished by reaction of these functionalities with di-tert-butyl dicarbonate under phase transfer ...
TL;DR: Starting from tetrachloroacetone 1 and (carbomethoxymethylene)triphenylphosphorane 4, the title compound 16 was prepared in five steps in 44% yield.
Abstract: Starting from tetrachloroacetone 1 and (carbomethoxymethylene)triphenylphosphorane 4, the title compound 16 was prepared in five steps in 44% yield. Spectroscopic and chromatographic data indicated...
TL;DR: In this paper, the right and left-handed helices of poly(dG-dC)•poly(DG-DC) with sodium counterions were characterized using infrared spectroscopy in the 1750-700 cm−1 region.
Abstract: Infrared spectroscopy in the 1750–700 cm−1 region is used to characterize the right- and left-handed helices of poly(dG-dC)•poly(dG-dC) with sodium counterions. The use of polymers selectively deut...
TL;DR: Using a radioimmunoassay to measure the relative potencies of a wide range of chemically modified structures related to the H-type 2 human blood group determinant, evidence was accumulated that the...
Abstract: Using a radioimmunoassay to measure the relative potencies of a wide range of chemically modified structures related to the H-type 2 human blood group determinant, evidence was accumulated that the...
TL;DR: In this article, the electronic absorption spectra of coumarin and its derivatives, including umbelliferone, esculetin and scopoletin, were investigated.
Abstract: The electronic absorption spectra of coumarin and its derivatives umbelliferone (6-hydroxycoumarin), esculetin (6,7-dihydroxycoumarin), and scopoletin (6-methoxy-7-hydroxycoumarin) were investigate
TL;DR: In this article, the Taft-Kamlert π* (dipolarity-polarizability) range −0.08 to 1.00 was determined for a solution of 5 -8 C5 -C16 alkane liquids.
Abstract: Heats of solution of 5 – 8 C5–C16 alkane liquids have been determined in each of 19 organic solvents covering the Taft–Kamlert π* (dipolarity-polarizability) range −0.08 to 1.00. Enthalpies of alka...
TL;DR: The photolysis of pyruvic acid vapour has been studied at wavelengths of 366, 345, and 320 nm, at a temperature of 340 K and pressures from about 1 to 10 Torr as mentioned in this paper.
Abstract: The photolysis of pyruvic acid vapour has been studied at wavelengths of 366, 345, and 320 nm, at a temperature of 340 K and pressures from about 1 to 10 Torr. Products observed were CO2 and CH3CHO...
TL;DR: In this article, the intrinsic barriers of eight identity SN2 reactions X−, X++ CH3X+CH3X→ XCH3+X− are calculated at the 4-31G computational level, and the distortion energy and its C-X stretching and H-C-X bending components can be calculated directly, or alternatively, estimated from the force constants and bond dissociation energies of CH 3X.
Abstract: At the 4-31G computational level, the intrinsic barriers of eight identity SN2 reactions X− + CH3X → XCH3 + X− are less than the energies required to distort CH3X from its ground state geometry to its transition state geometry by a constant 25 kcal/mol. The distortion energy and its C—X stretching and H—C—X bending components can be calculated directly, or, alternatively, estimated from the force constants and bond dissociation energies of CH3X. Regardless of the mode of computation, the distortion energies are found to be dominated by the C—X stretching deformations, and these are linearly correlated with the intrinsic barriers. The total deformation energies are also linearly correlated with the intrinsic barriers. The transition vectors of the eight identity reactions have been calculated; each is dominated by the C—X stretch. The percentage of C—X stretching at the transition state, here termed the Distortion Index (DI), reflects the "tightness" or "looseness" of this structure. The intrinsic barrier ...
TL;DR: In this paper, the energy properties of hydrogen abstraction reactions with R, X≡H, CH3, NH2,OH, and F have been studied at the abinitio 6-31G -UHF level.
Abstract: Hydrogen abstraction reactions with R, X≡H, CH3, NH2,OH, and F have been studied at the abinitio 6-31G – UHF level. However, energetic properties were computed at the CI level. Rate constants and A...
TL;DR: In this paper, the photoconductivity of a series of perylene tetracarboxyl-dimides has been studied by delayed-collection-field and electric field induced fluorescence quenching techniques.
Abstract: Photoconductivity of a series of perylene tetracarboxyl-dimides has been studied by delayed-collection-field and electric field induced fluorescence quenching techniques. It has been shown that the...
TL;DR: In this article, the reaction of zinc octaethylporphyrin with N2O4 in dichloromethane gives, in a stepwise reaction, the zinc complexes of mono-, di-, tri-, and tetra-nitrooctaethyl porphyrins.
Abstract: The reaction of zinc octaethylporphyrin with N2O4 in dichloromethane gives, in a stepwise reaction, the zinc complexes of mono-, di-, tri-, and tetra-nitrooctaethylporphyrins. Demetallation, under ...
TL;DR: In this article, the radius of micelles of several block copolymers in different selective solvents (for both types of blocks) was determined from photon correlation spectroscopy.
Abstract: Hydrodynamic radius of micelles of several block copolymers in different selective solvents (for both types of blocks) was determined from photon correlation spectroscopy. The boundaries of micella...
TL;DR: The product obtained from the reduction of potassium permanganate by trimethylamine in aqueous phosphate buffers has been identified as a soluble form of colloidal manganese dioxide which is stabil
Abstract: The product obtained from the reduction of potassium permanganate by trimethylamine in aqueous phosphate buffers has been identified as a soluble form of colloidal manganese dioxide which is stabil
TL;DR: In this paper, the authors determined densities and viscosities for the binary systems of m-cresol with aniline, N-methylaniline and N-dimethyleniline at five different temperatures.
Abstract: Densities and viscosities were determined for the binary systems of m-cresol with aniline, N-methylaniline, N, N-dimethylaniline, N-ethylaniline, and N, N-diethylaniline at five different temperatures. From the experimental results, the excess volume, excess viscosity, excess molar free energy of activation of flow, excess partial molar volume, and partial molar volumes were calculated. Also various thermodynamic parameters of activation of flow were calculated from the dependence of viscosity on temperature. The deviations from ideality of thermodynamic and transport functions are explained on the basis of molecular interactions between the components of the mixture.
TL;DR: Experimental measurements of the gas phase ion equilibria with a high pressure mass spectrometer combined with the recent determination of hydrogen bond dissociation enthalpies and free energies for the hydrogen bihalide ions are discussed in this article.
Abstract: Experimental measurements of the gas phase ion equilibria X− + HX = XHX−, X−(HX)n−1 + HX = X−(HX)n, and X− + HY = XHY where X, Y = Cl, Br, I, with a high pressure mass spectrometer, combined with the recent determination of F− + HF = FHF− by Larson and McMahon, provide a very complete set of hydrogen bond dissociation enthalpies and free energies for the hydrogen bihalide ions. The bond energy trends in the different XHX− and XHY− are discussed. The data can be used also for the evaluation of lattice energies of salts containing the bihalide ions and for determinations of the solvation energies of these ions.
TL;DR: In this paper, the sorption of uranyl species on a hematite sol of narrow size distribution has been studied as a function of uranium concentration and solution pH, and the adsorption increases with increasing uranium content in the solution.
Abstract: The sorption of uranyl species on a hematite sol of narrow size distribution has been studied as a function of uranium concentration and solution pH. The adsorption increases with increasing uranium content in the solution. Raising the pH from 5 to about 6.2 markedly enhances the uptake of uranium. The enhanced uptake coincides with a proportional increase of . The sudden increase in adsorption around this pH region does not appear to be due to changes in surface charge of the hematite particles. It may be due to specific interactions between and the hematite particles. Results of desorption experiments show that different binding sites may exist on the hematite surface.