摘要:

The polarized Raman spectrum ofs-trioxane has been measured in single-crystal phase I, the melt, and the chloroform-dsolution and the measurements used to improve the assignments, particularly in the C—H stretching region.

ISSN:0008-4042    

DOI:10.1139/v79-116

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The catalytic reaction between carbon monoxide and nitrous oxide over chromium(III) oxide has been investigated in a continuous flow system at atmospheric pressure from 525 to 583 K. Two kinetic regions with apparent activation energies of 172 ± 4 kJ mol−1(525 to 559 K) and 239 ± 4 kJ mol−1(565 to 583 K) were observed. The rate-controlling step in both regions was associated with the formation of an intermediate carbonate-like species during the consecutive decompositions of two nitrous oxide molecules. In the region of higher apparent activation energy, the presence of polymeric surface chromate groups may influence the reactivity of any carbonate-like intermediate and the subsequent desorption of carbon dioxide thereby leaving a vacant site for nitrous oxide decomposition.

ISSN:0008-4042    

DOI:10.1139/v79-117

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The reaction of tertbutyllithium with 1-phenylphosphorinan-4-one yields a mixture of isomeric alcohols which are partly separated as their P-sulfides. This mixture is dehydrated by P4S10to afford 1-phenyl-4-tertbutylphosphorin-3-ene sulfide. This sulfide with nickelocene and allyl iodide gives a P(III) → Ni(II) complex which reacts with P(OMe)3to yield a methylphenylphosphorinenium salt. This salt with BuLi and cyclohexanone gives the corresponding open chain product, i.e. a hexa-3,5-dienylphosphine oxide. This oxide is reduced by HSiCl3to the corresponding phosphine which is characterized as its P → Fe(CO)4complex. The phosphorinene sulfide is metalated on C(2) byn-butyllithium in THF. The lithium derivative with acetone yields a mixture of 'cis' and 'trans' alcohols which are separated and fully characterized. Significant variations of2J(H–P),3J(H–P) coupling constants and ν(OH), ν(P=S) ir frequencies are observed between the two isomers. The mixture of 'cis' and 'trans' alcohols is dehydrated to give a endo-exocyclic diene which is not isomerized when reacted with Fe3(CO)12. A reduction-complexation of the P=S group is observed instead. The 2-lithio-phosphorinene is also reacted with iodine to afford a bridged dimer.

ISSN:0008-4042    

DOI:10.1139/v79-118

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The quantitative PMO analysis of theab initiowavefunction of a molecule A—B is based upon a partitioning of the Fock matrix elements of this wavefunction to obtain the fragments A and B, followed by computation of the stabilizing and destabilizing orbital interactions between the orbitals of these fragments that contribute to the HOMO of A—B. However, when one or both of the fragments is NH2or a congeneric species, neither the 3a1nor the 1b1orbital of this fragment is appropriate for overlap with the second fragment, and the PMO analysis cannot be performed. A solution to this problem is proposed, and has been tested by application to various conformational properties of methylamine.

ISSN:0008-4042    

DOI:10.1139/v79-119

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Chemical oxidation of (−)-bornyl acetate provides a mixture of 3-, 5-, and 6-oxobornyl acetate, whereas microbiological hydroxylation with cultures ofHelminthosporiumsativumgives a mixture of 2,3-, 2,6-, and 2,5-bornanediols. In each case the reaction occurs preferentially at the C(5) position. Microbiological hydroxylation of (+)-bornyl acetate withH.sativumoccurs almost exclusively at the C(5) position. Regiospecific hydroxylation of (+)- or (−)-bornyl acetate with cultures ofFusariumculmorumalso occurs at the C(5) position but without concomitant hydrolysis of the acetoxy group.

ISSN:0008-4042    

DOI:10.1139/v79-120

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The structure, absolute configuration and physical constants of nojigiku alcohol ((+)-6-exo-hydroxycamphene) and derivatives have been established by synthesis from (−)-isobornyl acetate.

ISSN:0008-4042    

DOI:10.1139/v79-121

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Novel lyotropic mesophases that spontaneously orient in magnetic fields have been prepared using hexadecylpyridinium chloride and hexadecyltrimethylammonium bromide as well as, in limited regions, mixtures of the two detergents. These mesophases of type II provide the opportunity to study the behaviour of oriented water (DOH) at the hydrophobic interface, sodium ions, and the effect on hydrocarbon chain motions of variations in composition of the constituent bilayers formed by the mixed detergent systems. The pyridinium head group is especially accessible to definitive studies using deuterium magnetic resonance spectra of specifically deuteriated ring and adjacent hydrocarbon chain segments. Such investigations reveal the lack of cylindrical symmetry of motion about the extended chain axis near the pyridinium head group.The deuterium resonance of the HOD species shows that both pyridinium and trimethylammonium head groups have a very small orienting effect on the adjacent water, which appears to be indifferent to the choice of these chemical identities. This is understandable in terms of the lack of hydrogen bonding to these moieties. Sodium ions also exhibit small quadrupole splittings in all systems studied here and thus probably play a passive role in the interface chemistry and structure.

ISSN:0008-4042    

DOI:10.1139/v79-122

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

31P and77Se nmr spectra have been measured for a range of phosphorus(V) selenides, diphosphorus(V) diselenides, and triphosphorus(V) triselenides in the inert solvent CH2Cl2and in liquid SO2. Significant roughly-correlated reductions in |1J(PSe)| and deshielding of the77Se resonance accompany change of solvent from CH2Cl2to SO2. These changes are shown to arise from 1:1 phosphorus(V) selenide:SO2donor:acceptor complex formation. Approximate thermodynamic constants for the formation of the complexes have been determined and possible structures for the 1:1 complexes with the diphosphorus(V) diselenides discussed. It is shown from1H and31P nmr spectral changes that Ph2P(CH2)2PPh2forms a 1:1 complex with SO2, and approximate thermodynamic data for the SO2complexation of the diphosphine have been established. Complexation is indicated by changes in both |1J(PTe)| and δPwhen (Me2N)3PTe is dissolved in SO2, but the chemical reactivity of this system precluded detailed study.

ISSN:0008-4042    

DOI:10.1139/v79-123

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Mercury(II) cyanide forms 1:2 complexes with triphenylphosphine and tri-p-tolylphosphine. Both 1:1 and 1:2 complexes are formed with tricyclohexylphosphine but only the 1:1 complex is obtained with tri-tert-butylphosphine, and no complex is formed with tri-o-tolylphosphine. The complexes have been characterized by elemental analyses and by infrared and Raman spectral measurements. Their behaviour in solution has been investigated by conductance, molecular weight, and31P nmr measurements. The infrared and Raman data for the 1:2 complexes are in accord with a pseudotetrahedral structure ofC2vskeletal symmetry. At least one of the 1:1 complexes is indicated to have a dimeric structure involving terminal and bridging CN ligands. The C≡N, Hg—CN, and Hg—P stretching frequencies and the31P—199Hg spin–spin coupling for the complexes are discussed.

ISSN:0008-4042    

DOI:10.1139/v79-124

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Seventeen new mixed-ligand complexes of As(III) and Sb(III) with dithio-ligands have been prepared and studied. The preparation of the mixed-ligand complexes has been made by reacting the corresponding iodobis(dialkyldithiocarbamate) complexes with either CS2and HNR2or the sodium salt of the dithiocarbamate. Alteration of the second method facilitated the preparation of the mixed-ligand dithiocarbamate–xanthate complexes of Sb(III) whereas the analogous arsenic compounds have not been isolated. The study of these new compounds reveals that their stability depends on the nature of both ligand and central atom. The spectroscopic data of the compounds are discussed and compared with those of similar complexes of Bi(III).

ISSN:0008-4042    

DOI:10.1139/v79-125

出版商:NRC Research Press    

年代:1979

数据来源: NRC