摘要:

The proton magnetic resonance spectrum of bis(2,2-dichlorocyclopropyl) ether consists of two partially overlapping ABX spectra due to the meso andd,lisomers. A study of the temperature dependence of the spectra in different solvents demonstrates the existence of complex formation with benzene. It is found that for the most abundant isomer the heat of formation of the complex is −1700 ± 100 cal/mole, entropy of formation is −6.2 ± 0.3 e.u. The association shifts are 52 ± 2 c.p.s., 64 ± 5 c.p.s., and 88 ± 5 c.p.s. at 60 Mc/s for the three protons situated at different points in the molecule.

ISSN:0008-4042    

DOI:10.1139/v63-273

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

Heats of vaporization of 14 alcohols, having from one to five carbon atoms, have been determined in a Calvet microcalorimeter, using a special technique. The method consisted of allowing the alcohol to vaporize into a vacuum, the heat required for the vaporization being provided by passing a current through a resistance wire which was immersed in oil in a U-tube surrounded by the alcohol. The additivity scheme previously devised by Laidler for heats of formation and related properties was applied to the results, and the agreement with experiment was within a few tenths of a percent.

ISSN:0008-4042    

DOI:10.1139/v63-274

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

The interaction of boron halides BX3(where X is Cl or Br) or aluminum halides Al2X6(where X is Cl, Br, or I) with hydrazine is characterized by the elimination of hydrogen halide and the formation of substances with boron– (or aluminium–) nitrogen linkages. The hydrogen halide appears in the products as hydrazine hydrohalide, which can be separated by a hydrazine washing technique, leaving a polymeric material with empirical formula MN4H5(where M is Al or B). A reaction scheme is proposed and possible structures of this polymeric product are discussed.

ISSN:0008-4042    

DOI:10.1139/v63-275

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

Oxidation of 1,3:2,5-di-O-methylene-L-rhamnitol yielded 2,5:4,6-di-O-methylene-1-deoxy-L-arabo-3-hexulose, which was characterized as its 2,5-dichlorophenylhydrazone and by reduction to derivatives ofL-rhamnitol and of 6-deoxy-L-talitol. Oxidation of 2,5-O-methylene-L-rhamnitol 1-benzoate yielded a syrupy 3,4-diketose which was characterized as the crystalline quinoxaline derivative. Attempts to convert 1,2:4,5-di-O-isopropylidene-D-mannitol 6-benzoate to a ketose were unsuccessful.

ISSN:0008-4042    

DOI:10.1139/v63-276

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

Sodium chloride has been found to increase the ammonia yield from Co60γ-irradiated cystine in 0.02 MH2SO4. The effect is attributed to the participation of chlorine atoms, which deaminate the amino acid to a greater extent than hydroxyl radicals. The ratio of the rate constantsis determined to be 24 in 0.02 MH2SO4.

ISSN:0008-4042    

DOI:10.1139/v63-277

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

trans-9-trans-12-Octadecadienoic acid was found to be a component of the glyceride oil of the seeds ofChilopsis linearis(Cav.) Sweet. It was isolated by fractional crystallization of the acids at low temperatures and removal of conjugated acids as their adducts with maleic anhydride. Identification was made by absorption spectra and by preparation of derivatives and degradative products. The acid is estimated to constitute about 15% of the total fatty acids of the oil. Linoleic acid was also identified.

ISSN:0008-4042    

DOI:10.1139/v63-278

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

The structure of metachloral is established by n.m.r., infrared, and dipole moment studies.

ISSN:0008-4042    

DOI:10.1139/v63-279

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

L-Arabinose-5-C14was synthesized by the following route:D-xylose → D-gulono-1,4-lactone-1-C14 → 2,3:5,6-di-O-isopropylidene-D-gulono-1,4-lactone-1-C14 → 2,3-O-isopropylidene-D-gulono-1,4-lactone-1-C14 → 3,4-O-isopropylidene-2,5-L-arabino-urono-lactone-5-C14 → methyl-α,β-L-arabinofuranosido-methyl uronate-5-C14 → methyl-α,β-L-arabinofuranoside-5-C14 → L-arabinopyranose-5-C14. The overall radiochemical yield ofL-arabinose-5-C14was about 14% based on KC14N used in the first step. The structures of the isopropylidene derivatives ofD-gulono-lactone have been clarified.

ISSN:0008-4042    

DOI:10.1139/v63-280

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

Samples of poly (methyl methacrylate) have been made in toluene solution at −30° C withn-butyllithium initiator. Different monomer and initiator concentrations were used to obtain products of different overall molecular weights; polymerization times were varied to achieve partial as well as complete polymerization. The polymer samples were divided into fractions which were examined as to molecular weight and microstructure. It was found that the whole polymers have unusually wide molecular weight distributions which can be attributed to a combination of two narrower distributions, one of which occurs at a low and the other at a higher molecular weight region. This "double peak" phenomenon was observed for polymers at lower conversions as well as for polymers representing complete conversion of monomer. Proton magnetic resonance measurements showed that the degree of isotacticity of various fractions of a whole polymer is not the same at all molecular weights.In one case a second portion of monomer was polymerized after the complete polymerization of a first portion. Comparison of the molecular weight distribution before and after the second addition of methyl methacrylate indicated that polymer chains in all molecular weight regions, above a very low minimum value, are capable of further addition of monomer.

ISSN:0008-4042    

DOI:10.1139/v63-281

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

The thermal decompositions of tetramethyltetrazene (TMT) and tetraethyltetrazene (TET) have been studied using a flow system. It is shown that both the decompositions occur at, or above, the limiting pressure for unimolecularity, and Arrhenius parameters for both decompositions are obtained. The decomposition mechanism is discussed in relation to the Arrhenius parameters and theories of three-fragment decompositions. Preliminary values of some kinetic parameters for some reactions of dialkylamino radicals are presented.

ISSN:0008-4042    

DOI:10.1139/v63-282

出版商:NRC Research Press    

年代:1963

数据来源: NRC