摘要:

The zero-field ODMR of triplet state of chlorophyllbin n-octane has been carried out. The ODMR parameters measured at various fluorescence wavelengths suggest that Chlbis probably present in more than two ligated species in which water serves as the ligand.

ISSN:0008-4042    

DOI:10.1139/v86-031

出版商:NRC Research Press    

年代:1986

数据来源: NRC

摘要:

Ion/molecule reactions between the ion C3H4+•ion, from allene and neutral alkanes were investigated by mass spectrometry. There are four H•/CH3•/H−/H2−transfer reactions and relative rate constants were calculated. The overall rates increased in the order CH4 < C2H6 < C3H8 < i-C4H10 < n-C4H10. There is also a stabilization process by alkanes of CeH8+•ion species, but its importance is lower than the above transfer processes.

ISSN:0008-4042    

DOI:10.1139/v86-032

出版商:NRC Research Press    

年代:1986

数据来源: NRC

摘要:

Activity coefficients were determined at 293.15 K for the more dilute component in 24 binary solutions of nonelectrolytes, by gas-chromatographic analysis of the equilibrium vapor phase. One component of the binary mixture was either nitromethane, nitroethane, 1-nitropropane, 2-nitropropane, ethanenitrile, propanenitrile, ethyl ethanoate, or butyl ethanoate; and the other component was either heptane, 1-heptene, or 1,6-heptadiene.From the limiting activity coefficients of these components, some factors that affected their magnitude were identified. The values were also used to test the modifications of Prausnitz, Blanks, and Weimer, of Helpinstill and Van Winkle, and of Keller, Karger, and Snyder to the Scatchard–Hildebrand equation modified to accommodate polar components. In addition, the degree of constancy of the ratio of the dipole – induced dipole interaction parameter for a series of solutes in one solvent to that in another was considered.

ISSN:0008-4042    

DOI:10.1139/v86-033

出版商:NRC Research Press    

年代:1986

数据来源: NRC

摘要:

Two products, 2,7-dioxa-1,4,4,5-tetramethylbicyclo[3.2.1]octane-3,6-dione (5), and 2-acetonyl-2,3,3-trimethylsuccinic anhydride (4) were identified from the base-catalysed reaction of camphoronic acid,2(R′, R″ = CH3), with acetic anhydride. The former (5) is believed to be identical with the product described by Fittig and assigned an isomeric formulation.

ISSN:0008-4042    

DOI:10.1139/v86-034

出版商:NRC Research Press    

年代:1986

数据来源: NRC

摘要:

The differential heats of dilution oftert-butanol into water-tert-butanol mixtures were measured at 26.90 °C. The results in the range where the mole fraction oftert-butanol,x, is less than 0.05 indicate that the hydrophobic interaction is repulsive and of long range; the interaction appears to extend its tail as far as six molecular distances or longer. Above the threshold concentration, the differential heats of dilution were close to zero and approximately independent of concentration and temperature.

ISSN:0008-4042    

DOI:10.1139/v86-035

出版商:NRC Research Press    

年代:1986

数据来源: NRC

摘要:

Sterically hindered porphyrins having a fully hydrophobic cavity have been prepared. The cavity is capped with a 2,3,5,6-tetramethylbenzene moiety containing at the 1,4-positions methylene —(CH2)n— chains (n = 4, 5, 7) bonded attranspyrrole rings of a porphyrin that is alkylated with methyl or ethyl groups at the other β-pyrrolic positions. The iron(III) chloride derivative of the 4,4-durene-capped base has been obtained as single crystals, and subjected to X-ray structural analysis. The typical high spin, square pyramidal geometry of five-coordinate hemin chlorides is maintained; the porphyrin core is strongly distorted and there is no interaction between the phenyl group of the strap and the iron.

ISSN:0008-4042    

DOI:10.1139/v86-036

出版商:NRC Research Press    

年代:1986

数据来源: NRC