摘要:

The complete analysis of the proton magnetic resonance spectrum of epichlorohydrin as 10 mole% solutions in benzene and in acetonitrile is reported. Extensive tickling experiments demonstrate that thecisoidcoupling constants over four bonds are negative, while the correspondingtransoidcoupling constants are positive. Detailed results for the benzene solution, in which the non-equivalent protons of the —CH2Cl moiety have almost identical chemical shifts, show that although all the resonances may be unequivocally identified and measured to a high order of precision (± 0.03 Hz), an iterative computer fit (LAOCOON-3) has a larger uncertainty for the derived parameters than indicated by the "probable errors" furnished by the computer program. Analysis of the acetonitrile solution, however, furnishes a less ambiguous result. In addition, it is noted that use of relative apparent intensities of resonance peaks can lead to the wrong sign of those coupling constants whose magnitudes are near zero.

ISSN:0008-4042    

DOI:10.1139/v70-173

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Complete analyses of the proton magnetic resonance spectra of propylene oxide, epifluorohydrin, epibromohydrin, and epiiodohydrin shows that in all cases thecisoidcoupling constants over four bonds are negative, and thetransoidcoupling constants positive. Dipole moments, together with the vicinal coupling constants of the CH—CH2X moiety, are used to establish the probable conformations for all the epihalohydrins. Conformational factors appear to obscure any possible relationship between substituent electronegativity and long-range coupling constants.

ISSN:0008-4042    

DOI:10.1139/v70-174

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The kinetics of the hydrogen-ion-independent pathway for the replacement of fluoride in aqueous (NH3)5CoF2+by H2O have been reinvestigated using a specific fluoride-ion electrode, with due regard for the concomitant autocatalytic loss of the ammine ligands. In perchlorate media of ionic strength 0.1 M, the first-order rate coefficient is 1.22 × 10−6 s−1at 45°, and the kinetics are represented by ΔH* = 24.4 kcal mole−1and ΔS* = −9 cal deg−1 mole−1over the range 35–75° at least. The relationship of these data to those for the aquation of other species of the type ML5Xn+is discussed.

ISSN:0008-4042    

DOI:10.1139/v70-175

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

From 910 to 1089°K, at pressures of 20 to 36 mm, the pyrolysis of ethylbenzene in a toluene carrier flow system occurs primarily by three reactionsThe Arrhenius equation for the reaction [1], logk1(s−1) = 14.7 − (70 100/2.3RT), is in agreement with a previous aniline carrier study and with thermochemical calculations. Reaction [11] is surface dependent and yields widely scattered results. For experiments in a conditioned quartz vessel, logk11(s−1) = 9.06 − (51 700/2.3RT). Values ofk1andk12are unaffected by the nature of the surface and by changes in the surface-to-volume ratio. The rate constants for reaction [12] are somewhat scattered, but yield the approximate equation logk12(s−1) = 12.7 − (64 000/2.3RT).E1should possibly be increased by about 1 kcal to allow for the effect of reaction [−1], the recombination of methyl and benzyl species.

ISSN:0008-4042    

DOI:10.1139/v70-176

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The luminescence behavior of the compounds Ag3[CrxCo1−x(CN)6] has been found to differ in several respects from that of the related compounds K3[CrxCo1−x(CN)6]. In the silver compounds at room temperature, the Co(III)3T1gemission is too weak to be seen; the Cr(III)2Egemission appears to be quenched to a greater extent, and is displaced about 1.5 kK to higher energy. At 77 °K, where the Co(III)3T1gemission can be seen, it is found to be displaced about 0.5 kK to higher energy. These effects, and also the shifts of the [Cr(CN)6]3−and [Co(CN)6]3−absorption bands in the reflectance spectra of the compounds, are discussed on the basis of interaction of the Ag+ion with the [Cr(CN)6]3−and [Co(CN)6]3−ions. Furthermore, the variation of Cr2Egemission intensity with mole percent Cr has its maximum at a lower Cr concentration in the silver salts, indicative of more extended interaction between Cr3+ions than in the potassium salts.

ISSN:0008-4042    

DOI:10.1139/v70-177

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

A well-resolved electron spin resonance spectrum has been observed from frozen aqueous, methanol/water mixtures, and acetonitrile/water mixtures of potassium manganocyanide. Hyperfine splitting from at least two manganese atoms is present. The sharpness of the lines indicates that a rate process capable of averaging the anisotropic dipole–dipole interactions is operative. These results are discussed in terms of the known chemical and magnetic properties of Mn(II)/cyanide systems. It is suggested that an exchange process involving low-spin and high-spin manganese ions in the same molecule occurs.

ISSN:0008-4042    

DOI:10.1139/v70-178

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The radiolysis of liquid ethane at 195°K gives as major products H2, C2H4, andn-C4H10. Minor products are CH4and C3H8. The initial yields of H2and C2H4can only be determined indirectly due to the high rate of H-atom addition to product ethylene.c-C5H8in low concentration effectively scavenges H atoms and hence protects C2H4. The derived initial yields are:G(H2) = 5.97,G(C2H4) = 2.96,G(CH4) = 0.44, andG(C3H8) = 0.55. The yields of scavengeable H atoms and C2H5radicals are 2.29 and 5.81, respectively. The problem of direct measurement of initialG(H2) values for saturated hydrocarbons at low temperatures is discussed.

ISSN:0008-4042    

DOI:10.1139/v70-179

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The reaction intermediates of K[Pt(ac)X3] with ethylenediamine and its N-substituted derivatives have been studied in water and organic solvents. The general reaction iswhere ac = (CH3)2C(Y)C≡CC(Y)(CH3)2, en = ethylenediamine, Y = OH, OCH3, and X = Cl, Br. The five-coordinate intermediates2are isolated and characterized from conductivity data, molecular weight determinations, and infrared, nuclear magnetic resonance (n.m.r.), and ultraviolet (u.v.)-visible absorption spectra. The stability of complexes2(see equation above) in terms of alkyl substitution of the NH2groups is approximatelyenMe4 > enMe2Et2 > enH2Me2 > enwhere enMe4 = (CH3)2N(CH2)2N(CH3)2, enMe2Et2 = CH3C2H5N(CH2)2NC2H5CH3, enH2Me2 = CH3HN(CH2)2NHCH3, enEt4 = (C2H5)2N(CH2)2N(C2H5)2. In contrast to these reactions, the Zeise salt, K[PtC2H4Cl3], reacts with ethylenediamines and gives only stable, bridged compounds of the formula (PtC2H4Cl2)2(en). Bridged compounds, (Pt(ac)Cl2)2(en), are also obtained with K[Pt(ac)Cl3], but only in the presence of a large excess of KCl in the reaction solutions.

ISSN:0008-4042    

DOI:10.1139/v70-180

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The preparation of (CH3S)2AlCH3and (CH3S)3Al from trimethylaluminum and methanethiol is reported. The reaction of CO2, COS, and CS2with (CH3S)2AlCH3yields (CH3S)3C—C(CH3S)3and thiocarbonates respectively, besides dimethyl disulfide. With the same disubstituted aluminum derivative, phenylacetylene reacted to give C5H5C(SCH3)CH2. A study with deuterated phenylacetylene has permitted us to establish the mechanism of this reaction.

ISSN:0008-4042    

DOI:10.1139/v70-181

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The stereochemical course of the reaction of some 7,8-dicarboxylate derivatives of 1,3,5,5-tetramethyl-bicyclo[2.2.2]oct-2-ene with bromine has been established. The proton magnetic resonance parameters of these products are discussed.

ISSN:0008-4042    

DOI:10.1139/v70-182

出版商:NRC Research Press    

年代:1970

数据来源: NRC