摘要:

The results of an ultraviolet photoelectron spectroscopic study of the thermolysis of 5,5-dimethyl-1-phenyl-Δ3-1,3,4-triazoline-2-thione (1) are presented. That CS2is one of the major products establishes that carbon monosulfide (CS) is formed as a reaction intermediate in the thermolysis. Other products of thermolysis of1are molecular nitrogen and isopropylidenephenylamine (2). The photoelectron spectrum of the latter is also reported. Thermolysis of1in solution also leads to CS, which polymerizes extensively in the absence of trapping agents but is partly converted to CS2in the presence of S8and to COS in the presence of cyclohexanone.

ISSN:0008-4042    

DOI:10.1139/v77-515

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

13C nmr spectra have been obtained for a series of benzene derivatives substituted with phosphorus-containing groups of the type PZ2, P(O)Z2, and P(S)Z2. Inductive and resonance substituent constants were determined from the shielding ofmetaandparacarbon atoms according to the dual-substituent parameter approach. Possible mechanisms of substituent effects of PIIIand PVderived functional groups are discussed and in some cases compared with effects of the analogous nitrogen derivatives.

ISSN:0008-4042    

DOI:10.1139/v77-516

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

Vicinal carbon–proton coupling constants have been determined for a series oftert-butyl derivatives and compared to the vicinal proton–proton coupling constants in the analogous series of isopropyl derivatives. In both series coupling constants were found to decrease with electronegativity of substituent, with3JC,Hdecreasing more rapidly than3JH,H. The relationship between the two types of coupling was found to beJC,H = 1.2JH,H − 3.5. The regular change in the ratio ofJC,HtoJH,Hindicates that substituent effects can be useful in predicting carbon–proton coupling constants from proton–proton models.

ISSN:0008-4042    

DOI:10.1139/v77-517

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

A study by Raman spectrometry of the system Al3+–H2C2O4in aqueous solution as a function of the acidity of the solution and of the ratiot = [metal]/[ligand] shows very clearly the successive formation of the complexes Al(C2O4)+, Al(C2O4)2−, and Al(C2O4)33−. The formation of the species Al(C2O4)+, which had been rejected by some authors, is confirmed and it was easily possible to identify its characteristic frequencies as well as those of the species Al(C2O4)2−. The27Al and13C nmr spectra confirm these results and allow the identification of each complex by means of a clearly characteristic signal. Moreover, the results of this study permit the rejection of the hypothesis of the formation of hydroxylated complexes, at least in important quantities.It also was possible to use the intensities of the Raman scattering bands at eight selected characteristic frequencies of the species Al(C2O4)+, Al(C2O4)2−, and Al(C2O4)33−to determine their distribution as a function of the acidity of the solution. [Journal translation]

ISSN:0008-4042    

DOI:10.1139/v77-518

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

The availablevalues for neutral organic compounds in aqueous solution can be fitted with useful precision by additivity schemes based on atomic, bond, or group contributions. For the set of 132 compounds these schemes require 11, 14, or 49 parameters and give weighted average deviations of 14, 9, or 6 J K−1mol−1. For acyclic molecules the atomic contributions scheme permits chemically useful estimates ofto be made for compounds of C, H, O, and N.

ISSN:0008-4042    

DOI:10.1139/v77-519

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

Nitrosation of pyridine aldehydep-tolylhydrazones2with amyl nitrite gives rise top-tolueneazopyridine aldoximes4which form stable tris chelates with cobalt(III). Spectral data (ir, uv, and1Hmr) indicate that the ligands exist mainly in the assigned azooxime structure4, and that their chelates have five-membered ring structure7. Also, the1Hmr spectra implymer-configuration9for the chelates examined. No evidence for the tautomeric nitrosohydrazone structure3for the ligands and thefac-configuration8for Co(III) chelates could be obtained. Using the HMO method, the azooxime form4for the ligand was shown to be more stable than the nitrosohydrazone structure3. Also, good agreement was obtained between observed transition energies and those calculated by the HMO method. The acid dissociation constants of the ligands in 50 vol% ethanol–water at 25 °C and ionic strength of 0.1 were determined spectrophotometrically.

ISSN:0008-4042    

DOI:10.1139/v77-520

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

Two new solid TCNQ complexes have been isolated, coronene–TCNQ 1:1 and 3:1. The infrared and electronic absorption spectra are presented for the two different stoichiometries. From these spectra we infer that the complexes are covalent in the ground state with a charge transfer band appearing at 730 nm. The out of plane vibrations of the individual molecules are noticeably perturbed upon complexation.

ISSN:0008-4042    

DOI:10.1139/v77-521

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

From 1,2-O-isopropylidene-α-D-glucofuranose1, the 6-amino-6-deoxy-l,2:3,5-di-O-isopropylidene-α-D-glucofuranose6was prepared in a four-step sequence in an overall 50% yield. The conversion of6to the 6-bromoacetamido-6-deoxy10, 6-deoxy-6-isothiocyanato11, and 6-(p-azido-o-nitroanilino)-6-deoxy12derivatives ofD-glucose is described.

ISSN:0008-4042    

DOI:10.1139/v77-522

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

A modified Maclnnes equation is presented and its relationships with Taft and Br0nsted equations discussed.

ISSN:0008-4042    

DOI:10.1139/v77-523

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

The mechanism of catalysis of aromatic chlorination by pyridine was investigated by measuring the rates of chlorination of toluene in acetic acid with and without added pyridine, pyridinium nitrate, or lithium chloride. All three increase the rate of chlorination slightly and to about the same extent. The effect on the second-order rate constant for chlorination ofp-chloranisole in chloroform was determined for pyridine, pyridinium chloride,N-ethylpiperidinium chloride, tetra-n-butylammonium chloride, and tetra-n-butylammonium perchlorate. Again, all additives increase the rate constant, with the increase being least for pyridine. It is concluded that, for chlorination in dilute solution, pyridine has no specific catalytic effect, but probably increases the rate by increasing the polarity of the medium. Tetra-n-butylammonium chloride was observed to have a decreasing accelerating effect on chlorination in chloroform as its concentration is increased. This was thought to be the result of complexation of chlorine as trichloride. The formation constant for tetra-n-butylammonium trichloride in chloroform was found by the Benesi–Hildebrand spectrophotometric method to be 17 ± 3 M−1. This, together with the previously determined value of 9 × 104 M−1for the corresponding tribromide, shows that the order of stability of trihalides in nonaqueous solvents iscontrary to an earlier report.

ISSN:0008-4042    

DOI:10.1139/v77-524

出版商:NRC Research Press    

年代:1977

数据来源: NRC