. Can. J. Chem. 62, 92 (1984). Carbon-13 and nitrogen-15 nmr chemical shifts of benzenediazonium salt and its para-substituted derivatives have been measured in sulfolane solutions. The chemcial shifts of I3C 1 correlate linearly with the polarographic half-wave potentials. This relation indicates the linear increase of electron densities at Cl with the increase of electron-donating power of the substituents. Non-linear relationships between "N shifts of both nitrogen nuclei and the half-wave potentials were partly attributed to the second-order paramagnetic contributions to the I5N shifts. This contribution is approximately proportional to the inverse of the uv absorption frequencies. Overall results suggest that in the ground state resonance structures of the benzenediazonium salts, the rehybridization of the Cl-Nl bond is very unlikely and this bond remains as a single bond.

Can. J. Chem. 62,1772(1984. The half-wave potentials (El/z) of polycyclic diazonium salts as well as those of the parent hydrocarbons, the corresponding aldehydes, and the nitro compounds, when plotted against the coefficient of the energy of either the lowest vacant orbital [Traduit par le journa(] Introduction In 1969, we reported the results of our work on the effect of substituents on the half-wave reduction potentials of aryl diazonium tetrafluoroborates in the aprotic solvent sulfolane (1). These results produced a good Hammett plot [l]. Only one reversible, one electron-reduction wave was observed.

. 65, 2770 (1987).Anodic oxidation of lactams in the presence of halide ions produced excellent yields of bicyclic compounds with reactants having rings in the range of eight to ten atoms (C7 to Cg). Smaller rings did not react to form bicyclic products and larger rings gave reduced yields. Attempts were made to cyclize non-cyclic amides and to bicyclize cycloheptyl and cyclooctyl acetamide with limited success. RICHARD M. ELOFSON, FAHMI F. GADALLAH et JAMES K. LAIDLER. Can. J. Chem. 65, 2770Chem. 65, (1987.Lorsqu'on soumet des lactames cycliques comportant de huit B dix atomes (C, i Cg) B une oxydation anodique en prtsence d'ions halogtnures, on obtient des composts bicycliques avec d'excellents rendements. Lorsqu'on soumet des composts cycliques plus petits i cette reaction, ils ne donnent pas de produits bicycliques alors que les composts dont le cycle est plus grand donnent de moins bons rendements. Lorsqu'on a essay6 de cycliser des amides non-cycliques ou de provoquer une bicyclisation des cycloheptyl-et cyclooctyl-acttamides, les rtsultats ont t t t mitigts.[Traduit par la revue] IntroductionWe have previously reported (1) the bicyclization of cyclic amines in moderate yields by anodic oxidation in the presence of halide ions, particularly bromide ion. Following the example of Edwards and co-workers (2-4) it was decided to attempt the bicyclization of a number of lactams by electrochemical means. Since amides are not readily attacked at anodes (5) and are much more resistant to chemical reagents, it was anticipated that more severe conditions in the form of higher anode potentials and/or higher temperatures might be required. On the other hand, since amides are resistant to direct anodic attack, any bicyclic products produced by indirect processes as described in the previous paper (1) should be safe from further degradation at the electrode. These postulates have been confirmed in the experiments described below.Because of the success with lactams it was decided to attempt to bicyclize cycloheptylacetamide and cyclooctylacetamide and to cyclize non-cyclic amides. These results, to date much less successful and preliminary in nature, are included only because no further work in this area is likely from this laboratory.

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