摘要:

Dihydromyrcene was irradiated with 1-MeV electrons at room temperature both in the pure state and in benzene solution. The main reactions observed, and theirG-values for the pure diisoprene, were loss of unsaturation (~7.8–9.9), cross-linking (or dimerization) (2.4–2.6), evolution of hydrogen (0.81), andtrans→cisisomerization (< 0.5). As with squalene, the loss of double bonds in dihydromyrcene occurred only in the cross-linked residue, obtained on distillation of the irradiated isoprenoid. Although the residue (mainly dimer, with some trimer) was considered to be partially cyclized, no cyclization of uncross-linked (monomeric) dihydromyrcene was observed. Dihydromyrcene in 10% benzene solution (by weight) showedtrans→cisandcis→transisomerization withG-values of 0.63 and 1.2, respectively, hydrogen evolution with aG-value of 0.08, and a higher rate of loss of original unsaturation than in the pure state.

ISSN:0008-4042    

DOI:10.1139/v67-024

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The precise determination of drop-times for micropolarographic mercury electrodes in aqueous inorganic electrolytes with and without the addition of organic surface-active compounds is described. A dependable mathematical method for conversion of drop-times to accurate surface tension data and the use of IBM computer techniques for the calculation of double layer parameters are discussed. Experimental results for hydrochloric acid, potassium chloride, and furfurylamine systems are reported.

ISSN:0008-4042    

DOI:10.1139/v67-025

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

Infrared spectra in the region 350 to 3 200 cm−1have been recorded fors-trinitrobenzene ands-trinitrobenzene-d3. An assignment of 13 of the 15 infrared active vibrations of both molecules has been made. The assumption thats-trinitrobenzene is planar withD3hsymmetry is supported by the analysis of the infrared spectrum. Vibrations involving the nitro groups are virtually unchanged upon deuteration ofs-trinitrobenzene.

ISSN:0008-4042    

DOI:10.1139/v67-026

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The compressibility of acetone has been redetermined at temperatures of 25 to 55 °C, and at pressures from atmospheric to 1 kbar. The results have been fitted to the Tait equation, and values of (∂P/∂T)Vand of the internal pressure have been calculated. The heat capacity at constant volume has also been deduced as a function of pressure and temperature. The variations in these and other derived quantities have been shown to lead to conclusions about structural changes in the liquid.

ISSN:0008-4042    

DOI:10.1139/v67-027

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The rhodium/selenium system has been examined by room temperature X-ray powder diffraction patterns and by differential thermal analysis. A tentative phase diagram has been obtained. Eleven phases were observed, five of which were previously known. The compounds β-RhSe1.29, α-RhSe1.32, and α-RhSe1.34have lattices based on the B81structure; RhSe2+xand RhSe2.67have defect pyrite lattices. The compound α-RhSe1.95is isomorphous with IrSe2. The structures of RhSe1±0.1, β-RhSe1.34, α- and β-RhSe1.50, and RhSe1.9are not yet known.

ISSN:0008-4042    

DOI:10.1139/v67-028

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

Coordination complexes between α-cyanoacetamide as ligand and the group (IV) halides as Lewis acids have been prepared. In all these compounds the ligand has been found to be a bidentate, coordinating to two different metal atoms. The infrared results indicate coordination through the nitrogen of the cyano group and one of the donor atoms of the amide group, probably nitrogen. Some physical properties of the complexes strongly suggest that they are coordination polymers.

ISSN:0008-4042    

DOI:10.1139/v67-029

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

Infrared spectra of aqueous solutions containing Ce(IV) and nitrate ions have been obtained by the attenuated total reflectance (a.t.r.) technique. Vibration frequencies and intensities have been measured and compared with infrared transmittance spectra and Raman spectra of both solutions and solids. The number of bands and the variation of band intensity with concentration changes indicate the presence of nitrato–cerium complexes in the solution. The polarization of the 1 538 cm−1Raman band is advanced as a criterion that the coordination between the nitrate ion and the cerium(IV) ion is bidentate. Possible assignments are considered although many of the vibrations are characteristic of the ligand and hence are not diagnostic of a particular species.

ISSN:0008-4042    

DOI:10.1139/v67-030

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

With dimethyl mercury and dimethyl cadmium as sources of methyl radicals, values ofk1/k21/2for the reactionshave been calculated from 471 to 527 °C over the pressure range 0.3 to 16.2 cm. Extrapolation to the effective infinite pressure region, where it is assumed thatE2= 0, givesE1= 9.3 kcal mole−1, logA1= 10.8 (cc mole−1s−1).

ISSN:0008-4042    

DOI:10.1139/v67-031

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

Photochemical synthesis of mono- and bi-substituted cyclopentadienyl–manganese–tricarbonyl compounds with triphenyl-phosphine, arsine, stibine, and bismuth is reported. The infrared absorption and proton magnetic resonance spectra are discussed in relation to the distribution of negative charges among the ligands. The dipole moments were measured and the partial dipole moments for the group manganese–triphenyl compound in these derivatives are calculated and discussed.It is shown that the distribution of negative charges occurs principally between the CO and phenyl ligands and that the donor–acceptor behavior of the phenyl ligands depends mainly on the phenyl group and to a very small extent on the central atom.

ISSN:0008-4042    

DOI:10.1139/v67-032

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The kinetics of bromination of six substituted styrènes (3-fluoro-, 3-chloro-, 3-bromo-, 3,4-dichloro-, 3-nitro-, and 4-nitro-) in anhydrous acetic acid have been investigated at several temperatures. At 25.3 °C the reactions follow the rate expressionThe rate constants for the second order process show a good linear free energy relationship of the logkversus σ type with ρ = − 2.24. (The value obtained at 35.3 °C is − 1.93.) No simple rate-substituent dependence is obtained for the more complex third order process. Activation parameters have been obtained for the second order brominations, the ΔS≠values being large and negative. Bromination of styrene in the presence of a large excess of acetate or nitrate gives only two products in each case, the α,β-dibromide and the α –acetoxy β-bromide or α -nitrato- β -bromide respectively.The magnitude of the reaction constant ρ, the values of ΔS≠, and the reaction products all support a mechanism involving a highly unsymmetrical bromonium ion intermediate.

ISSN:0008-4042    

DOI:10.1139/v67-033

出版商:NRC Research Press    

年代:1967

数据来源: NRC