摘要:

Crystals of the pyridine solvate of bis(8-hydroxyquinoline)silver(I), Ag(C9H9NO)C9H6NOHO•C5H5N, are monoclinic, space groupP21/a, with cell dimensionsa = 10.87 ± 0.01 Å,b = 10.65 ± 0.01 Å,c = 16.70 ± 0.01 Å, β = 92.6 ± 0.2°,Z = 4. Atomic parameters have been determined from a three-dimensional analysis using 2163 independent intensities to which no absorption corrections were applied. Refinement was by observed and calculated differential syntheses using isotropic temperature factors. The final discrepancy index isR = 0.116.The coordination of the silver atom is distorted tetrahedral, with bonds to the phenolic oxygen and ring nitrogen atoms of both 8-hydroxyquinoline molecules. Adjacent bis(8-hydroxyquinoline)silver molecules are linked by a hydrogen bond between two oxygen atoms. The pyridine molecules are held in the lattice by van der Waals' forces.

ISSN:0008-4042    

DOI:10.1139/v68-079

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The acetaldehyde pyrolysis has been studied over the 480–540 °C temperature range, and at pressures from 1 to 560 mm Hg. Measurements were made of the rates of production of the major product methane and of the minor products hydrogen, ethane, acetone, and propionaldehyde. The kinetic effects of adding carbon dioxide, of changing the surface:volume ratio, and of coating the vessel have been determined. The elementary processes are found to occur largely in the gas phase. The dissociation of CH3CHO into CH3 + CHO is deduced from the rates of hydrogen and ethane formation; there is significant falling off of the rate constants at lower pressures. The kinetic parameters for the reaction CH3 + CH3CHO → CH4 + CH3CO are obtained, and it is suggested that quantum-mechanical tunnelling plays a role. Acetone production has an activation energy of 12.4 kcal/mole and it is concluded that its formation involves the participation of the isopropoxy radical, the activation energies being as indicated:

ISSN:0008-4042    

DOI:10.1139/v68-080

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

135I was incorporated into TlI, AgI, HgI2, CuI, and PbI2and phase changes in the solid were studied by the Hahn emanation technique of following the emanation of the135Xe daughter. Good agreement was obtained with results previously obtained by conventional techniques.

ISSN:0008-4042    

DOI:10.1139/v68-081

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The activities of Li2ZrCl6, Na2ZrCl6, and K2ZrCl6in the systems LiCl–Li2ZrCl6, NaCl–Na2ZrCl6, and KCl–K2ZrCl6, respectively, were calculated from available pressure data using a modified form of the Gibbs–Duhem relationship. The calculations indicate positive deviations from ideality that decrease with increasing size of the alkali metal cation.

ISSN:0008-4042    

DOI:10.1139/v68-082

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The1H and19F spectra of pentafluorobenzene (PFB) have been analyzed, and spectral parameters obtained by iteration using least squares criterion. A number of solutions were found by this procedure. The physical solution was selected by "tickling" experiments.

ISSN:0008-4042    

DOI:10.1139/v68-083

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

By the application of a modified form of Onsager's equation to dilute solutions of glycerol in isopropyl alcohol and isobutyl alcohol, and conversely to dilute solutions of each of the latter two alcohols in glycerol, it is found that the apparent solution moments of these alcohols, at the condition of infinite dilution, are 2.68, 1.61, and 1.66 D respectively over the temperature range 30 to 50 °C.

ISSN:0008-4042    

DOI:10.1139/v68-084

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The n.m.r. spectra of all the methyl-substituted benzene complexes of chromium tricarbonyl, molybdenum tricarbonyl, and tungsten tricarbonyl have been obtained. The unusual features include a large upfield shift of alkene proton chemical shifts on complex formation, but within the metals the order of increasing shift is Cr > W > Mo, a non-periodic trend. It has also been observed that the individual alkene proton chemical shifts in an unsymmetrical methyl benzene become markedly different on complex formation, in contrast to the behavior found in the free arene. Symmetrical methyl-substituted benzene metal complexes, on the other hand, show the same symmetry characteristics as the free arenes, and hence, on an n.m.r. time scale, there is no permanent distortion of the ring. A theory is presented, invoking partial three-point bonding of the M(CO)3moiety to the arene ring. This bonding is postulated to occur most strongly at arene carbon atoms bearing methyl groups and, as a consequence, results in an abnormally strong electron withdrawal from carbon positions meta to this carbon, even though this meta position may be unsubstituted.

ISSN:0008-4042    

DOI:10.1139/v68-085

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The dipole moments of bromochloromethane, bromodichloromethane, bromotrichloromethane, dimethylcarbamyl chloride, dimethylcarbamyl fluoride, vinyl formate, phenyl chlorothiolformate, γ-valerolactone, and 2-iodopropene were determined in dilute benzene solutions at 25 °C. The observed magnitudes of the dipole moments are rationalized in terms of molecular electronic charge distributions.

ISSN:0008-4042    

DOI:10.1139/v68-086

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The Hg(63P1)-sensitized decomposition of HNCO vapor has been briefly studied at 26 °C with HNCO pressures from about 3 to 30 Torr. The products detected were the same as in the direct photolysis, CO, N2, and H2. The quantum yield of CO was appreciably less than unity, compared with a value of 1.5 in the direct photolysis under similar conditions. From this and other observations it is tentatively concluded that a single primary process occurs:From a study of the mercury-photosensitized reactions in mixtures of HNCO with H2, it was concluded that hydrogen atoms react with HNCO to form CO but not N2. The initial step is probably addition to form NH2CO. From the competition between reaction [1] and the corresponding quenching by H2, the cross section for reaction [1] was estimated to be 2.3 times that of hydrogen.

ISSN:0008-4042    

DOI:10.1139/v68-087

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The effect of NO at pressures up to 380 Torr on the photolysis of HNCO vapor (4.5 Torr) by light from an unfiltered medium-pressure mercury lamp has been studied at 37 °C. The yield of CO was reduced to about half its original value, which is attributed to reactions of NH and NCO with NO. The yield of N2showed a steady increase with increasing NO pressure, probably due to reactions of NO(A2∑+) excited by absorption of light. The hydrogen yield fell rapidly to zero as the NO pressure was increased.Added oxygen at pressures up to 5 Torr had no effect on the CO and N2production at 37 °C; at 110 °C the CO yield decreased somewhat while the N2remained unaffected. These observations suggest that NH and NCO do not react readily with O2. The production of H2fell rapidly to zero with increasing O2pressure at both temperatures. The suppression of H2formation by both NO and O2supports the belief that it is formed by reactions of hydrogen atoms.

ISSN:0008-4042    

DOI:10.1139/v68-088

出版商:NRC Research Press    

年代:1968

数据来源: NRC