摘要:

Retention of65Ni in neutron-irradiated Ni(CO)4has been measured both in the pure form and inn-heptane and Fe(CO)5solutions, and mixed with triphenylphosphineinn-heptane solution. Retention was found to be nearly 100% in all cases except with high concentrations of Fe(CO)5, where the retention dropped off strongly. It is concluded that the high retention is the result of rapid exchange of CO with inactive Ni(CO)4. The effect of Fe(CO)5is considered to be a hot-zone reaction. The presence of triphenylphosphinenickel tricarbonyl was found not to affect the retention in Ni(CO)4. This is taken to show that the65Ni atoms formed in crystallineremain trapped in the lattice.

ISSN:0008-4042    

DOI:10.1139/v70-607

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The kinetics of formation of mono- and dicarbonyl complexes in two successive stages by direct carbonylation of ruthenium(II) chlorides in dimethylacetamide solution have been studied at 65–80° and up to 1 atm CO by gas uptake techniques. Both stages are first order in ruthenium. Formation of the monocarbonyl is independent of CO pressure; dicarbonyl formation is first order in CO at low pressures with the order decreasing towards zero with increasing pressure, and shows an inverse chloride dependence from 0.1–2.0 Madded chloride. For both stages, the data are consistent with a mechanism involving predissociation. A similar mechanism is suggested for the corresponding reactions in 3 MHCl solution which had been studied earlier and which showed overall second-order kinetics.Discussion on the related formation of molecular nitrogen complexes of ruthenium(II) is presented.

ISSN:0008-4042    

DOI:10.1139/v70-608

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The reaction of hydrogen atoms, produced by electric discharge, with methyl cyanide vapor has been reinvestigated at seven different temperatures between 40 and 507 °C over a range of methyl cyanide flow rates from 2 to 25 μmoles/s. As in the previous limited investigation the products have been found to be hydrogen cyanide, methane, and ethane, but the present results indicate the presence of chain characteristics to a minor extent, propagated by CN. Kinetic parameters for formation of the products have been evaluated, askHCN = 3.55 × 10−12e−5816/RT;; and.

ISSN:0008-4042    

DOI:10.1139/v70-609

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The thermal decomposition of CH2N2, highly diluted in Kr, has been studied in shock waves by using time-of-flight mass spectrometry to follow concentration changes in the reacting gas. Observations were made at pressures 45 to 95 Torr and temperatures 820 to 1200°K. The principal products of reaction are C2H4, C2H2, and N2. The primary step appears to be a second order unimolecular decomposition of CH2N2into CH2and N2; for this step, logk = (9.61 ± 0.21) − (15 800 ± 1 000)/2.303RT(cal mole−1and cm3mole s units.) Some decomposition of CH2N2into HCN and NH is also indicated. The formation of C2H2is believed to occur through vibrationally excited C2H4, formed by reaction between CH2and CH2N2. Calculations using the R.R.K.M. theory indicate that 50 + 10% of the energy of this reaction appears as vibrational energy of the product C2H4.

ISSN:0008-4042    

DOI:10.1139/v70-610

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

From measurements of electronic spectra it is deduced that cobalt(II) is tetrahedrally coordinated in molten PbCl2, SnCl2, and BiCl3, whereas nickel(II) adopts a coordination in PbCl2and SnCl2which is close to octahedral. NiCl2is insoluble in BiCl3and is formed by the reaction of NiS and BiCl3whereas CoS is soluble in BiCl3. Solutions of Pd(II), Pt(II), Rh(III), and Ir(III) may be prepared in molten PbCl2but the spectra do not assist in assigning the coordination of the solute ions.

ISSN:0008-4042    

DOI:10.1139/v70-611

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

A concise matrix formulation of chemical exchange effects on a nuclear magnetic resonance (n.m.r.) spectrum using the Bloch equations is described. The method accommodates many-site exchange processes, site-dependent relaxation times, differing site populations, and saturation effects in a steady-state first-order spectrum. The simple two-site exchange system is analyzed in detail and saturation effects in this system are studied numerically. Alternative forms of the basic lineshape equation are derived, all of which are readily adapted to efficient computer calculations for complete lineshape fitting to obtain kinetic data for complicated chemical exchange processes.

ISSN:0008-4042    

DOI:10.1139/v70-612

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

A new metabolite has been isolated from the fungusMonochaetiacompta. The properties and reactions of the metabolite suggest that it is 6,8a-dihydro-4-acetyl-8-methyl-6-oxo-7(3-methyl-2-oxo)-pentyl-1 H-2-benzopyran-1-one (2a).

ISSN:0008-4042    

DOI:10.1139/v70-613

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

A series of α,α-disubstituted-α-hydroxythiolesters has been prepared from ketone cyanohydrins by the Pinner reaction. The esters have been characterized both by classical methods and by analysis of their i.r. n.m.r., and u.v. spectra.

ISSN:0008-4042    

DOI:10.1139/v70-614

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Direct combination of the Lewis acids, Me3M (where M = B, Al, Ga, or In), and the diamines, Me2N(CH2)nNMe2(wheren = 1, 2, or 3) has given two series of complexes. A range of 1:1 complexes can be isolated with Me2NCH2NMe2as ligand. With the other diamines, use of a 1:1 molar ratio of reactants yields crystalline 2:1 complexes with two moles of Me3M per mole of ligand. Excluding the reaction between Me3B and Me2NCH2NMe2, 2:1 complexes can be isolated by reacting the various Lewis acids with the appropriate molar quantity of the diamines. The complexes have been characterized by i.r. and proton n.m.r. spectroscopy and molecular weight measurements.A number of complexes of Me3Ga with methyl substituted ethylenediamines have been prepared and the effects of substitution on the nitrogen ligand atoms studied. Pyrolysis of these complexes has demonstrated the ready elimination of methane and has resulted in the formation of condensed Ga—N species.

ISSN:0008-4042    

DOI:10.1139/v70-615

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Two new tetrahydroprotoberberine alkaloids are reported, one fromCorydalisthalictrifoliaand the other fromCorydalistuberosa. The former is apparently identical with a previously described synthetic compound. The latter is a des-methyl derivative of the first. Both compounds are 13-methyltetrahydroprotoberberines in which the hydrogens at C-13 and -14 arecisto one another. An examination has been made of the p.m.r. spectra of the two new bases and of several 13-methyltetrahydroprotoberberines of established structure and stereochemistry. The spectra can be used to assign the relative stereochemistry of these 13-methyl compounds.

ISSN:0008-4042    

DOI:10.1139/v70-616

出版商:NRC Research Press    

年代:1970

数据来源: NRC