摘要:

The reaction between allene and hydrogen over unsupported palladium, platinum, iridium, rhodium, ruthenium, and osmium catalysts has been investigated in a static constant volume system between 70 and 149 °C for a wide range of reactant ratios. The orders of reaction with respect to hydrogen and allene were one and zero, respectively, and temperature independent. The overall apparent activation energies for unsupported platinum, iridium, palladium and rhodium were 17.7, 9.1, 6.4, and 17.4 kcal/mol, respectively. The catalytic activities of the unsupported metals were in the sequence Pd > Ir > Rh > Pt > Ru, Os. Selectivity was highest with palladium and rhodium, and least with iridium. The polymerization was highest with platinum and least with indium.

ISSN:0008-4042    

DOI:10.1139/v72-288

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Studies ontrans-Re(acac)2Cl2in the solid state, solution, and gas phases by spectroscopic and classical physical methods show that the compound is a monomer and not a dimer as previously claimed (2).cis-Re(acac)2Cl2, Re(acac)2Br2, Re(acac)2I2, and Re(dbm)2Cl2have been prepared for the first time and corresponding physical measurements are reported.

ISSN:0008-4042    

DOI:10.1139/v72-289

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

We have been unable to prepare TcCl6by the method published previously even though our reaction between Tc and Cl2gave products which appeared the same. TcO3Cl and TcOCl4have been prepared and fully characterized for the first time.

ISSN:0008-4042    

DOI:10.1139/v72-290

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Oxotetrachloroaquorhenium(VI), ReOCl4•H2O, has been prepared and characterized for the first time by analysis, infrared spectroscopy and single crystal X-ray diffraction. The crystals were orthorhombic,a = 10.834(8),b = 11.089(8),c = 5.517(4) Å,Pn21a,Z = 4. Intensity data were recorded by integrating film methods and measured with a Joyce–Loebl microdensitometer, and 624 observable of the 704 measured independent reflections were given non-zero weight in the final cycle of full matrix least-squares refinement whereR1 = 0.0572 andR2 = 0.0687. The molecular structure is based on a very distorted octahedron with a strongly bonded oxo-group (Re—O, 1.63(2) Å)trans(177(2)°) to a weakly bonded aquo-group (Re—O, 2.27 (2) Å). The Re—Cl distances do not differ significantly (2.29(1) Å av). The chlorine atoms are bent away from the oxo-group (angles vary from (94–102°(1)).

ISSN:0008-4042    

DOI:10.1139/v72-291

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The total synthesis of (±) ochrobirine is described.

ISSN:0008-4042    

DOI:10.1139/v72-292

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Several ferrocenylalkyl- and aryl ketyls were generated and their e.s.r. spectra were recorded. Pentadeuterio-benzoylferrocene and benzoyl perdeuterioferrocene were synthesized. Analysis of the e.s.r. spectra of their corresponding ketyls enabled the determination of the hyperfine splitting constants of benzoylferrocene ketyl, and allowed an assignment of the electron densities at various positions in the molecule.A comparison of the magnitudes of theg-values for the ketyls derived from benzophenone (2.0034), benzoylferrocene (2.0062), and 2,2-dimethylpropanoylferrocene (2.0126), combined with the proton hyperfine splittings, gave some insight into the nature of the interaction of the free electron with the ferrocene system.

ISSN:0008-4042    

DOI:10.1139/v72-293

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

A new alkaloid, nupharolutine, (C15H23NO2) has been isolated from the basic extract of the rhizomes ofNupharluteum. By spectroscopic and chemical methods it is shown to be a hydroxy derivative of deoxynupharidine. The mass spectra of the new base and several isomers are reported.

ISSN:0008-4042    

DOI:10.1139/v72-294

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The rate of reaction of O(1D2) with N2O relative to the rate of its reaction with neopentane has been determined by a competitive method. The value obtained,is in good agreement with several values in the literature. It is also found that N2O does not deactivate O(1D2) to O(3P) but reacts with it to form products.

ISSN:0008-4042    

DOI:10.1139/v72-295

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

A number of dialkyltin(IV)-bisfluorosulfates, -bistrifluoromethanesulfonates, and -bisdifluorophosphates are synthesized by solvolysis of dialkyltin(IV) chlorides in an excess of the corresponding acid according toR = CH3, C2H5,n-C3H7,n-C4H9, andn-C8H17; X = SO3F, SO3CF3, and PO2F2. The structural proposals, hexacoordination for tin with the alkyl groups intrans-octahedral position and bidentate bridging anionic groups with coordination through oxygen, are based on119Sn Mössbauer, infrared and, where obtainable, Raman spectra. The vibrational spectra of the difluorophosphates are discussed in detail. Variations in isomer shift and quadrupole splitting values with different alkyl groups in all three groups of compounds follow the same regular pattern as in the series R2SnF2. The results of point charge calculations are reported.

ISSN:0008-4042    

DOI:10.1139/v72-296

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The conformational dependence of the nuclear spin–spin coupling from methyl protons to ring protons, to the fluorine nucleus, and to protons of other methyl groups in toluene,p-fluorotoluene, and the xylenes is computed by the finite perturbation technique in the INDO approximation of molecular orbital theory. The calculated coupling over six bonds to the proton in the para position agrees quantitatively with experiment and its predicted dependence on the rotational angle of the methyl group supports a commonly assumed π electron mechanism for the transmission of spin information between the nuclei. Similar remarks apply to the fluorine nucleus inp-fluorotoluene. The couplings over five and four bonds to the protons in the meta and ortho positions display a more complex angular dependence and the former can be interpreted in terms of a dominant σ electron mechanism. The coupling between protons in different methyl groups in the ortho and meta xylenes is calculated as rather larger than the values observed in their derivatives and in the main shows the behavior expected from a π electron mechanism. Those conformations of ortho xylene in which the coupled protons are in close proximity yield computed values plausibly attributable to "direct" and/or "through-space" mechanisms. The preferred conformation of the methyl group in toluene is predicted to have a C—H bond eclipsing the plane of the aromatic ring and the calculated barriers to rotation of 0.013 kcal/mol in toluene and of 0.014 kcal/mol inp-fluorotoluene are in quantitative accord with microwave data.

ISSN:0008-4042    

DOI:10.1139/v72-297

出版商:NRC Research Press    

年代:1972

数据来源: NRC