摘要:

The mass spectra of exo-2-norbornyl chloride and several deuterated analogues have been examined in detail with particular regard to metastable peaks involving the molecular ions and norbornyl cations. The molecular ion does not undergo Wagner–Meerwein isomerization prior to fragmentation; in the norbornyl cation the hydrogen atoms have lost their identity as shown by random H and D loss when the ion ejects an ethylene molecule. Metastable ion analysis is proposed as a method for studying the participation of norbornyl carbonium ions in the preparation of 2-norbornyl chloride.

ISSN:0008-4042    

DOI:10.1139/v70-471

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Reduction of pyrazine (P) and tetramethylpyrazine (TMP) by sodium in the presence of sodium tetraphenylboride produces Na2P+and Na2TMP+, respectively. The electron spin resonance spectra of these species are presented and compared with those of the corresponding ion pairs. From line-broadening effects within the sodium hyperfine multiplets of the triple ion spectra, it is deduced that the sodium ions occupy positions close to the N–N axes of the ring systems.

ISSN:0008-4042    

DOI:10.1139/v70-472

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Crystals of disodium succinate have two distinct modifications, monoclinic and triclinic. These were recognized by electron spin resonance (e.s.r.) studies of. the free radicals produced by γ-irradiation. In the monoclinic crystals, e.s.r. spectra and radiation processes appear similar to those observed in γ- (or x-) irradiated succinic acid. The situation in triclinic crystals is more complex (see Part 2). In monoclinic crystals irradiated at 77 °K, two types of radical coexist. They were identified as−O2CCH2CH2ĊO22−,1, together with a distorted conformation of the radical−O2C(ĊHCH2)*CO2−,2. On warming to room temperature the former species disappears while the latter changes irreversibly to a stable conformation−O2CĊHCH2CO2−

ISSN:0008-4042    

DOI:10.1139/v70-473

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Electron spin resonance (e.s.r.) spectra and radiation processes in γ-irradiated triclinic crystals of disodium succinate are more complex than those observed in monoclinic crystals. At 77°K, three species coexist,−O2CCH2CH2ĊO22−(1), a distorted conformation of the radical−O2C(ĊHCH2)*CO2−(2), and an unidentified radical X. On warming to room temperature,1and X disappear, while2changes to a more stable conformation−O2CĊHCH2CO2−(3). In addition the species CO2−(4), and−O2CĊHCH3(5) are produced. On further warming to 40 °C, species4disappears while at the same time species3increases in intensity. Radical5remains unaffected. Possible mechanism and comparisons with monoclinic crystals are discus

ISSN:0008-4042    

DOI:10.1139/v70-474

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The proton spin – lattice relaxation time of aniline-d2in deuterated aniline solution was determined as a function of concentration and temperature over the temperature interval 260–360 °K using a pulsed nuclear magnetic resonance technique. In addition the proton spin – lattice relaxation time of aniline-d2in deuterated benzene solution at 20 °C was also determined. It was found that the activation energies of theintra- andinter-molecular relaxation rates were of similar magnitude, viz. 4.5 and 4.4 kcal/mole, respectively. It was also found that at 20 °C the rotational correlation time, τr, of the C6H5NH2molecule in infinitely dilute perdeutero benzene solution was approximately half that of the partially deuterated aniline molecule, viz. 3.0 × 10−12and 6.3 × 10−12 s, respectively, and that τrof C6H5ND2in infinitely dilute perdeutero aniline solution is much larger than in infinitely dilute perdeutero benzene solution and is equal to 19 × 10−12 s.

ISSN:0008-4042    

DOI:10.1139/v70-475

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The detailed report of the first cyclo-γ-cyanoethylation of an α,β-unsaturated carbonyl system, 3β-acetoxy-5α-pregn-17-en-21-al, is given. This reaction, which proceeds in high yields, gives rise, in a single operation, to products with an additional functionalized six-membered ring, primarily to allylic α′-cyanohexenols.

ISSN:0008-4042    

DOI:10.1139/v70-476

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

At room temperature the proton magnetic resonance spectrum of α,α-dichloro-2,4,6-tribromotoluene is ABX where the methine proton in the sidechain is X and is lying in the plane of the aromatic ring. At higher temperatures the ring proton spectrum, AB, broadens and eventually collapses to yield an A2X spectrum. From an analysis of the ring proton line shapes the barrier to rotation of the dichloromethyl group about the sp2–sp3carbon–carbon bond is obtained; ΔG* = 17.5 ± 0.1 kcal/mole at 304°K, ΔH* = 15.67 ± 0.08 kcal/mole, ΔS* = −7 e.u.,Ea = 16.38 ± 0.08 kcal/mole, logA = 11.78 ± 0.23 where the least squares errors given should probably be multiplied by a factor of from 3 to 5 to take possible systematic errors into account. The barrier is about 2 kcal/mole higher than in α,α,2,4,6-pentachlorotoluene. The barrier to rotation arises from the conformation in which chlorine and bromine atoms are eclipsed.

ISSN:0008-4042    

DOI:10.1139/v70-477

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The solubilities of lithium, sodium, potassium, caesium, and ammonium thiocyanates and iodides, and of rubidium thiocyanate, in tri-n-butyl phosphate (TBP), have been measured. In general, the solubilities decrease with increasing cation size, but the values for the ammonium salts are anomalously high. This is shown to be due to hydrogen-bonding between NH4+and the phosphoryl oxygen of the solvent. The results are compared with those reported for other alkali metal salts in TBP.

ISSN:0008-4042    

DOI:10.1139/v70-478

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Dissolution of bismuth metal by tri-iodide ion in acidified potassium iodide medium has been studied using a rotating disc technique. The rate constant for the dissolution process,kT, in solutions 0.5 Min potassium iodide at 25.0 °C has been shown to be related to the square root of the disc angular velocity, ω, by the following expressionThe activation energy for this reaction was found to be 4.7 kcal mole−1. These data clearly establish that the rate of dissolution is determined by the rate at which tri-iodide ion is transported to the metal surface. In solutions of [KI] = 0.10 M, however, the rate determining step appears to involve diffusion of tri-iodide ion through a layer of BiI3which forms on the bismuth metal surface as the reaction proceeds.

ISSN:0008-4042    

DOI:10.1139/v70-479

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

119Sn Mössbauer and vibrational spectra for a number of SnF62−and SnCl62−complexes have been obtained. One fundamental for the SnF62−ion has been reassigned. Strong evidence for anion–cation interaction for (ClO2)2SnF6is obtained both from the vibrational spectra and from the Mössbauer spectra where a non-zero quadrupole splitting is found.

ISSN:0008-4042    

DOI:10.1139/v70-480

出版商:NRC Research Press    

年代:1970

数据来源: NRC