ISSN:0008-4042    

DOI:10.1139/v76-217a

出版商:NRC Research Press    

年代:1976

数据来源: NRC

摘要:

The hydrodesulfurization of benzothiophene (BT) and 2,3-dihydrobenzothiophene (DHBT) has been examined over a commercial cobalt molybdate on alumina and over an unsupported MoS2catalyst promoted with Co. The results, in particular the appearance of styrene among the products, support cleavage of the hetero-ring in BT as the initial step in the reaction sequence under our low-pressure conditions. Ethylbenzene is the predominant product from both BT and DHBT, although increasingly significant amounts of DHBT are dehydrogenated to BT with rising temperature.

ISSN:0008-4042    

DOI:10.1139/v76-217

出版商:NRC Research Press    

年代:1976

数据来源: NRC

摘要:

Condensation ofcis-9-methyl-2-decalone,9, with ethyl 2-pyrrolidineacetate,10, afforded a mixture of two isomeric vinylogous amides,11. Oxidation of either one pure isomer,11a, or the mixture11to the same pyridone,12, revealed that the two condensation products were stereoisomeric at a single carbon atom and not structural isomers. Reduction of11aafforded the amino ketone13. The structures assigned to11,12, and13are based on X-ray crystallographic analysis of13.Similarly, condensation of9with ethyl 2-piperidineacetate,14, afforded the isomers15aand15bboth of which were oxidized to the same pyridone,16. Reduction of15aafforded17. The structures assigned to15,16, and17are based on X-ray crystallographic analysis of17.

ISSN:0008-4042    

DOI:10.1139/v76-218

出版商:NRC Research Press    

年代:1976

数据来源: NRC

摘要:

Electronic interactions in vinylamines can be divided into nN − π conjugation, and effects arising as a consequence of the electron-withdrawing abilities (−I) of both the nitrogen and π-system. Dehydroquinuclidine represents an ideal model which minimizes nN − π conjugation, and exhibits a pe spectrum which indicates that both the nNand π-orbitals are stabilized by about 0.4 eV relative to quinuclidine and bicyclooctene respectively. This stabilization is proposed to be a consequence of −Ieffects of each group and/or rehybridization of the nitrogen. Similar inductive effects are assumed to operate in enamines which do not prohibit nN − π interaction. In these cases, strong conjugative effects are operative in addition to the −Ieffects.

ISSN:0008-4042    

DOI:10.1139/v76-219

出版商:NRC Research Press    

年代:1976

数据来源: NRC

摘要:

Very slow partial neutralization of 5 × 10−4to 6 × 10−2 Msolutions of AlCl3and Al(ClO4)3, using either finely ground dolomite or NH3as the base, resulted in the formation of polynuclear hydroxyaluminum cations without the appearance of any solid phases. Certain properties of the polynuclear cations did not change and no solids formed during an aging period of two years. The properties of the polynuclear cations examined were their rate of reaction with 8-hydroxy-quinoline and hydrolysis constants using formulas suggested in the literature. In contrast, the concentration of the polynuclears decreased, although very slowly, during aging. This decrease was accompanied by the appearance of a second type of polynuclear hydroxyaluminum cation, which apparently has the same OH/Al mole ratio but is much less reactive than the first type.

ISSN:0008-4042    

DOI:10.1139/v76-220

出版商:NRC Research Press    

年代:1976

数据来源: NRC

摘要:

Classical 3-D trajectory investigation of bromine and iodine atom recombination reactions in He, Ar, and Xe, performed earlier, are extended, using an improved sampling technique, to include a larger number of trajectories and a wider temperature range (200–1500 K). The three body potential energy surfaces used were assumed to be nearly additive, but otherwise were defined by the existing molecular beam and spectroscopic data and contained essentially no arbitrary parameters. The agreement between computed and experimental rate constants is reasonable, and is best if the third body is heavy and reaction proceeds via a bound complex, such as IXe. Orbiting inert gas – recombining atom intermediate dimers, XM*, where X = I or Br, contribute to the overall recombination reaction via XM* + X → X2 + M reaction, provided M is heavy. If M = He, this reaction path is negligible at all temperatures studied, again provided that X = I or Br.

ISSN:0008-4042    

DOI:10.1139/v76-221

出版商:NRC Research Press    

年代:1976

数据来源: NRC

摘要:

Variational calculations are reported on the 1snssinglet and triplet states of the helium atom, up to and includingn = 26. By suitable choice of terms in the expansion for the wave function, significant economies in computer time are possible, and we quote an example of a 12-term uncorrelated wave function which gives a lower energy than Pekeris' 220-term correlated wave function. The problems of extending these calculations to much highern(e.g.n > 100) to include states of astrophysical interest are enumerated.

ISSN:0008-4042    

DOI:10.1139/v76-222

出版商:NRC Research Press    

年代:1976

数据来源: NRC

摘要:

Calculations of electro-optical parameters by the modified first order approximation (MFOA) method have been extended to X2CZ (X = H, F, Cl, Br; Z = O, S) molecules with a view to investigate the transferability of these parameters. The diagonal and cross elements of the bond moment derivative matrix have been evaluated. Unique values of µC−Xare obtained for theA1species. The bond moment derivatives are found to be transferable amongA1andB1species. Transferability of the µC−ZinB1andB2species is obtained for thiocarbonyl halides. Bond moment derivatives with respect to angle deformations are not found to be very significant whereas other cross elements of the bond moment derivative matrix are found to be of high magnitude.

ISSN:0008-4042    

DOI:10.1139/v76-223

出版商:NRC Research Press    

年代:1976

数据来源: NRC

摘要:

The complexes of deprotonated thiazolidine-2-thione (ttz) with many transition metals have been prepared. Probable structures have been proposed for the complexes on the basis of chemical analysis, spectral data (infrared and visible), and magnetic susceptibility measurements. The ligand field parameters have been evaluated and are in keeping with the proposed structures.

ISSN:0008-4042    

DOI:10.1139/v76-224

出版商:NRC Research Press    

年代:1976

数据来源: NRC

摘要:

NiM(NCS)6, [NiL4][M(NCS)6], and [NiL6][M(NCS)6] (M = Sn(IV), Ti(IV); L = pyridine (py), 3-cyanopyridine (cpy), nicotinamide (nia), ethylnicotinate (ent), and ethylenediamine (en)) have been prepared and characterised by elemental analysis, magnetic moment, and infrared and electronic spectral studies. These studies suggest a thiocyanate bridged structure for NiM(NCS)6and a cationic–anionic structure for [NiL4][M(NCS)6] and [NiL6][M(NCS)6].

ISSN:0008-4042    

DOI:10.1139/v76-225

出版商:NRC Research Press    

年代:1976

数据来源: NRC