摘要:

The extent to which the calculated scavenging yields are affected by the form of the ion–electron special distribution decreases as the free ion yield increases. The increasing free ion yield may be due to larger electron ranges or to a larger dielectric constant. The free ion yields in neopentane and water are respectively 1.0 (due to large electron ranges) and 2.7 (due to large dielectric constant). The scavenging yields in neopentane calculated with three different forms of spacial distribution, using the forced diffusion (FD) approximation, are significantly affected by the form of the spacial distribution. The scavenging yields in water calculated with four different forms of spacial distribution, using the FD approximation, are all within the experimental error of the measured yields. Use of the prescribed diffusion (PD) approximation permits satisfactory yields to be calculated for neopentane, but leads to the unsatisfactory result that all of the secondary electrons in the liquid have the same range (delta function distribution YD). The scavenging yield curves obtained using the PD approximation for water did not have a steep enough slope even when the distribution YD was used; YD leads to a steeper slope than any other form of distribution. The PD approximation gives an overestimate of the breadth of the geminate neutralization time distribution. The calculated time required for half of the geminate neutralization reaction to occur is similar whether the FD or PD approximation is used, but the spread of the neutralization times is an order of magnitude greater from the latter than from the former. Calculations were also done for electron scavenging in methylcyclopentane and in methanol. Methylcyclopentane behaves like cyclohexane and methanol behaves much like water with regard to the kinetics of ion–electron reactions in the spurs.

ISSN:0008-4042    

DOI:10.1139/v72-439

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The logarithm of the pseudo-first-order rate coefficientkfor the aquation of Co(NH3)5X(3–n)+can be represented by a quadratic equation in the pressureP, or, better, bywherePis in kbar,is the volume of activation atP = 0, andxis the increase in the number of water molecules solvating the complex as it goes to the transition state. ForCl−, Br−,andat 25°and ionic strengthI = 0.1 MLiClO4/HClO4,−10.6, −9.2, −6.3, and +16.8 cm3mol−1, andx = 8.0, 4.1, 3.9, 1.9, and −4.2; for Xn− = NCS−, the mean ΔV*fromP = 0.001 to 2.5 kbar at 88° is −4 cm3mol−1. Detailed consideration of these data, especially their correlation with the molar volume of reaction by a straight line of unit slope forCl−, Br−, NO3−, and H2O, provides strong evidence for a dissociative interchange mechanism. Forthe separating entity is probably HN3rather thanFor Xn− = NCS−, aquation is incomplete, at practical complex concentrations; at 88.0°, 1 bar, andI = 0.1 MLiClO4/HClO4,k = 3.3 × 10−6 s−1and the stability constant of Co(NH3)5NCS2+is 490 M−1.

ISSN:0008-4042    

DOI:10.1139/v72-440

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The decomposition of gas mixtures containing ozone has been studied following a short duration u.v. light pulse. From an analysis of the O3decomposition curves for O3:N2and O3:H2O mixtures, it is shown that the relative rate of O(1D) reaction with H2O and N2isIt is also shown that less than6% of the O2, formed directly by photolysis, is in thestate. The water catalyzed decomposition of ozone is also discussed.

ISSN:0008-4042    

DOI:10.1139/v72-441

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Band progressions have been observed in the CH2scissoring region of the i.r. spectra of trimethylene oxide (C3H6O) and three of its deuterated analogs (α-d2, β-d2, and α,α′-d4). With the aid of the pure ring puckering transitions (published previously) and a simple theoretical model of puckering–vibrational interactions the absorptions have been assigned to combination tones of CH2scissoring vibrations with the ring puckering mode and its overtones. The scissoring fundamentals of the α- and β-methylene groups have been identified and assigned. Of all the vibrations for which combination progressions are observed, only the β-CH2scissoring mode of the normal compound exhibits significant differences between the ring puckering transitions in the ground state and the vibrational excited state.

ISSN:0008-4042    

DOI:10.1139/v72-442

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The vapor phase Raman spectra of trimethylene oxide (TMO) and two of its deuterated analogs (α-d2and β-d2) each show one sharp line on a weak, broad, and unresolved band in the CH2scissoring region. Under high resolution these lines are resolved into several components. They are assigned to the fundamentals of the scissoring mode of α-CH2(in-phase,A1symmetry, in the case of the normal and β-d2compound) and overlapping bands resulting from interaction with the low frequency puckering vibration. The agreement between Raman and i.r. data is excellent and the assignments are entirely consistent. Raman lines corresponding to the out-of-phase combination (B2symmetry) of the α-CH2scissoring vibration and the scissoring mode of the β-CH2group (in normal, α-d2and α,α′-d4TMO) cannot be resolved.

ISSN:0008-4042    

DOI:10.1139/v72-443

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Deuterium labeling and high resolution mass spectrometry have been utilized to delineate the modes of mass spectrometric fragmentation ofO-methyl oximes of α,β-unsaturated ketones and methyl substituted cyclohexanones. α,β-Unsaturated ketone and 2- and 4-methylcyclohexanoneO-methyl oxime ether derivatives fragment upon electron impact in a manner reminiscent of the carbonyl derivatives from which they were prepared. However, several fragmentation sequences characteristic of theO-methyl oxime ether group were observed.

ISSN:0008-4042    

DOI:10.1139/v72-444

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The reaction of vinylmagnesium chloride with a fatty acid or its ester in the presence of cuprous chloride gives a 1,6-diketone. Fromn-valeric acid,n-tetradecane-5,10-dione is obtained in 53% yield. From methyln-valerate, a mixture ofn-tetradecane-5,10-dione (33%) and 5-oxo-1-nonene (34%) is obtained.

ISSN:0008-4042    

DOI:10.1139/v72-445

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Doubling of some p.m.r. signals from some steroidal diastereoisomers following treatment with the shift reagent, (DPM)3Eu(III), is reported for the first time. Similar examination of the hemithioethyleneketal of methyl isopropyl ketone provided the first evidence for the diastereotopic nature of the methyl groups of the isopropyl moiety of this compound. The resolution of signals from diastereoisomers and the failure to detect the diastereotopic nature of the methylene protons of different hemithioethyleneketals is discussed briefly in terms of inhibition of free rotation in pseudocontact association.

ISSN:0008-4042    

DOI:10.1139/v72-446

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The thermal decomposition of a series of phenoxo complexes of copper (II), in solution, containing either trichlorophenoxo or tribromophenoxo ligands and a variety of neutral ligands, has led to a rather unique method for the synthesis of μ4-oxo-hexa-μ-halotetracopper(II) complexes. The yield of this complex was found to increase considerably with the ability of the solvent to autoxidize, and also with the addition of hydroperoxides.

ISSN:0008-4042    

DOI:10.1139/v72-447

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The dielectric constant (ϵ′) and loss factor (ϵ″) of solutions of (i) 8-hydroxyquinoline in cyclohexane, carbon tetrachloride,p-xylene and 1,4-dioxan, (ii)o-nitrophenol inn-heptane, cyclohexane, carbon tetrachloride, and 1,4-dioxan, (iii) 2,4-dinitrophenol in 1,4-dioxan, and (iv) 2,6-dinitrophenol also in 1,4-dioxan have been recorded at four microwave frequencies and at 25 °C. A comparison of the relaxation time data of 1-nitro-naphthalene with that of 8-hydroxyquinoline in a number of solvents indicates that a strong specific interaction occurs between the latter solute and the solvent 1,4-dioxan which leads to the formation of a complex. In addition, a comparative study of nitrobenzene ando-nitrophenol indicates a similar phenomenon. Strong interaction of the 1,4-dioxan with an atom or atoms in the chelated ring system appears to take place which produces a larger reorienting species than the solute molecule itself and appreciably lengthens the relaxation time, although the data do not establish the point of attachment of the 1,4-dioxan to the chelated ring. The complex formation is accompanied by an additional component to the dipole moment. For the dinitrophenols significant interaction with the solventp-xylene complicates the interpretation of the relaxation time data, although in the 2,4-dinitrophenol the formation of a complex is indicated in 1,4-dioxan.

ISSN:0008-4042    

DOI:10.1139/v72-448

出版商:NRC Research Press    

年代:1972

数据来源: NRC