摘要:

Wide line nuclear magnetic resonance studies of trimethylamine complexes of BF3, BCl3, BBr3, and BH3show that rotation of methyl groups and rotation about the B—N axes occur in the solid phases. The complex between ammonia and boron trifluoride has also been studied.

ISSN:0008-4042    

DOI:10.1139/v70-086

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The effects of structural changes on the rates of hydrolysis of a series of thiochloroformate esters in water have been investigated. The reactivity is enhanced by increased electron donation by the hydro carbon group. These results, the activation parameters for the hydrolysis of methyl thiochloroformate and the solvent deuterium isotope effect, are shown to be consistent with the operation of the SN1 mechanism.

ISSN:0008-4042    

DOI:10.1139/v70-087

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The effect of pressure on the rate of spontaneous solvolysis oft-butyl chloride in ethanol–water mixtures in the range 0 to 40 %v/v ethanol at 0 °C has been measured up to a maximum pressure of 3 kbar. The results have been examined from several points of view and the conclusions are briefly described in the summary.

ISSN:0008-4042    

DOI:10.1139/v70-088

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The crystal structure of triclinic rubidium dichromate has been determined by single crystal X-ray diffraction. The crystal belongs to space groupwitha = 13.554,b = 7.640,c = 7.735 Å, α = 93.64°, β = 98.52°, γ = 88.80° and has four Rb2Cr2O7units in the unit cell. The final weighted agreement index after refinement by least-squares analysis is 0.058. The configuration of the dichromate ions is similar to that found in most other dichromate structures (Cr—O (bridging) = 1.78 Å, Cr—O (terminal) = 1.62 Å). The two non-equivalent Cr—O—Cr angles are 123 and 137°. The rubidium ions are surrounded by either 8 or 9 oxygen atoms at distances ranging from 2.86 to 3.31 Å. The structure of triclinic Rb2Cr2O7is similar, but not identical, to that of triclinic K2Cr2O7.

ISSN:0008-4042    

DOI:10.1139/v70-089

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The metal ion catalyzed chlorination of 1-chlorobutane, 1-chlorohexane, methyl-pentanoate, and methyl-heptanoate by protonatedN-chloroamines proceeds by a free radical chain mechanism and the chain carrying species was shown not to be a chlorine atom, but an amino radical cation.

ISSN:0008-4042    

DOI:10.1139/v70-090

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

TheN-haloamine halogenation of 1-chlorobutane in 4 Msulfuric acid in acetic acid as solvent is a radical chain process in which aminium radicals are the principal hydrogen atom abstracting species. WithN-chloroamines, a concurrent chlorine atom chain is promoted by impurities such as molecular chlorine, hydrogen chloride, and chloride ion.

ISSN:0008-4042    

DOI:10.1139/v70-091

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The kinetics of the radical chain chlorination of decanoic acid byN-chlorodimethylamine andN-chloropiperidine in 2 and 4 MH2SO4in acetic acid have been examined at 30°. The rate of reaction is proportional to the decanoic acid concentration and to the square root of the rate of chain initiation. The rate controlling step for propagation involves the attack of an aminium radical on decanoic acid, and termination involves the self-reaction of two aminium radicals. The latter reaction may involve the prior, rapid deprotonation of one or both radicals. The propagation rate constant has been estimated to be in the range 7 × 102to 1 × 104 M−1s−1and the termination rate constant to be in the range 6 × 106to 5 × 107 M−1s−1.

ISSN:0008-4042    

DOI:10.1139/v70-092

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Triarylsilylmethylmetallic reagents have been prepared by several routes: metalation; addition of phenyllithium to vinyltriphenylsilane; direct synthesis; and by halogen–metal exchange. The latter method is highly superior as regards both generality of application and yields. Dibromomethylsilanes undergo halogen-metal exchange at −78°, and reaction of the product with hydrogen bromide serves as a valuable way of converting geminal dibromides to monobromides. The organometallic reagents have been characterized in several ways, in particular by carbonation to give the related carboxylic acid.

ISSN:0008-4042    

DOI:10.1139/v70-093

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

not available

ISSN:0008-4042    

DOI:10.1139/v70-094

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The formalin condensation of 2,4-di-t-butylphenol and 2,4-di-t-butylaniline yields the benzoxazine2which, on hydrolysis, gives the hydroxybenzylaniline3a. In contrast to a report by Kulievetal. (2, 3) the condensation of equimolar quantities of 4-t-butylphenol,o-toluidine, and formaldehyde yieldsN-(2-hydroxy-5-t-butylbenzyl)-o-toluidine (4), rather than 2-amino-3-methyl-2′-hydroxy-5′-t-butyldiphenylmethane (5).

ISSN:0008-4042    

DOI:10.1139/v70-095

出版商:NRC Research Press    

年代:1970

数据来源: NRC