摘要:

Primary aliphatic amines can be characterized by infrared spectroscopy as to the nature and degree of branching of the alkyl chain, using the fundamental antisymmetric and symmetric NH2stretching frequencies measured in dilute C2Cl4solution. Where steric and direct conjugation effects are absent both frequencies and the integrated intensity of the antisymmetric band increase linearly with decreasing inductive electron-donating power of the alkyl chain. The integrated intensity of the symmetric band, which is smaller than that for the antisymmetric band in all the 26 compounds studied, is independent of the inductive nature of the alkyl chain as a first approximation. These results indicate that the N-atom lone-pair orbital in RNH2plays a negligibly small role in modifying the inductive effect of R on NH2frequencies and intensities as long as the N-atom hybridization remains sp3.

ISSN:0008-4042    

DOI:10.1139/v67-262

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

Most primary alkyl, primary α-substituted alkyl, and primary aromatic acid amides exhibit three sharp concentration and temperature dependent absorption bands at 3 518 ± 3, 3 504 ± 4, and 3 486 ± 8 cm−1, in dilute (0.003 Mor less) CCl4solution, just below the fundamental antisymmetric NH2stretching vibration. These are tentatively assigned to the shifted antisymmetric NH2stretching vibration in cyclic dimers, cyclic trimers, and cyclic tetramers respectively, with increasing NH … O hydrogen bond strength. In all alkyl amides the antisymmetric NH2band intensity exceeds the symmetric band intensity. Conjugation of the CONH2group with π-electron systems reverses this intensity relationship, except where the acidic NH2group can form intramolecular hydrogen bonds. These observations substantiate the previously published views on the nature of the vibrational mechanism of the NH2group. No evidence is found for enolization of amides in CCl4solution.

ISSN:0008-4042    

DOI:10.1139/v67-263

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The activation parameters ΔH≠, ΔS≠, and ΔCP≠for the hydrolyses of a series of alkyl chloroformates and dimethylcarbamyl chloride in water have been determined. The results indicate that, with increasing electron donation to the chlorocarbonyl group, the mechanism changes from bimolecular to unimolecular(SN1)displacement at this position. For isopropyl chloroformate, some concurrent alkyl–oxygen bond fission is also indicated. The bimolecular mechanism involves reversible addition of water to the carbonyl group followed by ionization of the carbon–chlorine bond.

ISSN:0008-4042    

DOI:10.1139/v67-264

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The spectra of PdCl2, K2PtCl4, K3RhCl6, and K3IrCl6in fused LiCl–KCl eutectic at 450 °C are reported. The rhodium(III) and iridium(III) species are shown to exist as MCl63−octahedral complexes with lower values of Δ and higher values of β than in aqueous solution. The palladium system is believed to contain the essentially octahedral PdCl64−complex which has a small tetragonal distortion, whereas for the platinum(II) species a purely tetragonal classification is more appropriate.

ISSN:0008-4042    

DOI:10.1139/v67-265

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The present work suggests that the chelate UO2(C9H6NO)2.C9H6NOH can be crystallized from chloroform as orange-red crystals which are monoclinic, space groupP21witha = 14.98 Å (σ = 0.03 Å),b = 20.38 Å (σ = 0.05 Å),c = 14.75 Å (σ = 0.03 Å), and β = 115.32° (σ = 0.20°). It is believed that six molecules are in the unit cell: three sets of molecules in the general positions (2a). The uranium positions have been established and show the higher symmetryP21/mwith four atoms in general positions and two atoms in the pseudo mirror planes. The molecular arrangement of 8-quinolinol molecules around the more general uranium atoms has been obtained from three-dimensional Fourier syntheses. This arrangement of 8-quinolinol molecules is essentially the same as found by Hall, Rae, and Waters in the adduct UO2(C9H6NO)2.C9H6NOH.CHCl3. The molecular arrangement around the two remaining uranium atoms has not been established because of false detail introduced by the pseudo-symmetry. This is enhanced by pronounced termination of series errors in theb-axis direction.

ISSN:0008-4042    

DOI:10.1139/v67-266

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

Stepwise stability constants have been determined for the 1:1 and 1:2 Eu3+:mandelate−and Eu3+:tartronate2−complexes in water. Measurements were made at low ionic strength and the temperature was 25 °C. The solvent-extraction–radiotracer method was used.For the mandelate system at an ionic strength of 0.104,K1 = 5.0 × 102,K2 = 1.58 × 102, andK1:K2 = 3.1. TheK1:K2ratios suggest monodentate ligandcy.The stepwise stability constants for the two stages of tartronate ion association are:K1 = 7.1 ( ± 15%) × 104andK1K2 = 4.2 ( ± 5%) × 108. The magnitudes of the stability constants suggest that tartronate is a tridentate ligand. The stability constant ratios are discussed with reference to the ratios for piperidinedicarboxylate and iminodiacetate complexes.

ISSN:0008-4042    

DOI:10.1139/v67-267

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The radiolysis of methylcyclohexene (MCH) vapor was carried out under a variety of conditions. TheG-values of the main products at 110°, extrapolated to zero dose, are hydrogen (5.2), methylcyclohexene isomers (2.0), ethylene (1.5), methane (1.3), propylene (0.8), and total dimer (0.3). Other products were also measured.The hydrogen yield was reduced toG = 3.1 by each of the additives, N2O, SF6, and CCL4, and toG = 1.6 by C2H4. Both DI and ND3increased the total hydrogen yield above the value in pure MCH. In pure MCH approximately 50% of the ions (G(total ionization) = 4.4) resulted in hydrogen formation, whereas in the presence of DI or ND3, 75% of the ions are hydrogen precursors. Thus three different types of positive ions are distinguished in the system:G(M1+) = 2.1,G(M2+) = 1.3, andG(N+) = 1.0.The average ion lifetime with respect to neutralization was 10−3s. The ion DI−was therefore stable with respect to decomposition to D + I−for a period greater than 10–3s under the conditions of the experiments (~380 Torr MCH, 110°).The yield of methylcyclohexene isomers increased with increasing temperature and increased upon addition of ND3or C2H4to the radiolysis system. The dimer yield was also enhanced by the addition of ND3. This effect was explained by the occurrence of an ionic secondary reaction that destroys methylcyclohexene and (or) methylcyclohexyl radicals in pure MCH.Approximately 85% of the methane is produced by methyl radicals abstracting hydrogen atoms from MCH.

ISSN:0008-4042    

DOI:10.1139/v67-268

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

There is a radiation-induced chain reaction in methylcyclohexane (MCH) – CCl4mixtures in the vapor phase at 110° and 380 Torr. The chain-propagation products are chloroform and methylcyclohexylchloride (Gmax ≈ 40) and the chain-termination products are mainly methylcyclohexene (MC), bimethylcyclohexyl (C14), and hexachloroethane, depending on the composition of the mixture. At CCl4concentrations < 1 mole%, HCl is formed mainly by reaction of Cl−with positive ions, e.g. Cl− + C7H14+ → HCl + C7H13. The value of the ratioG(MC)/G(C14)is 8 ± 1 in pure MCH and in the mixtures up to 44 mole% CCl4.There is a radiation-induced chain reaction in MCH–N2O mixtures in the vapor phase. At 110° and 380 Torr,G(N2) = 22,G(MC) = 16, andG(C14) = 1.6, independent of N2O concentration between 2 and 10 mole%. TheG-values are independent of MCH pressure between 50 and 520 Torr. Product formation is inhibited by the addition of SF6or DI. The half-life of the ion N2O−with respect to decomposition to N2 + O−is 10−4–10−3s under these conditions. It is suggested that the mechanism contains the reactionsReaction [24] is slightly exothermic. Reaction [25] is exothermic if the electron affinity of N2O is greater than that of C7H13.

ISSN:0008-4042    

DOI:10.1139/v67-269

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The35Cl nuclear quadrupole resonance frequencies of the trimeric and tetrameric phosphonitrilic chlorides have been studied as a function of temperature. Two forms of the tetramer were used and the differences in their spectra ascribed to crystallographic effects. Correlation of each of the lines in the trimer to a set of chlorine atoms in the unit cell were attempted using crystallographic data.

ISSN:0008-4042    

DOI:10.1139/v67-270

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The Raman spectrum of potassium thiocyanate has been recorded at various temperatures between − 195 and 185 °C. The predicted factor-group splitting of the C—N stretching vibration in the crystal at room temperature has been observed. The spectra of the two crystalline phases differ mainly in the lattice region. The far-infrared spectrum has also been recorded, and the existence of lattice modes at 25–30 cm−1is shown to be doubtful.

ISSN:0008-4042    

DOI:10.1139/v67-271

出版商:NRC Research Press    

年代:1967

数据来源: NRC