MUONIUM ADDUCTS OF BENZALDEHYDE - STRUCTURAL CORRELATION WITH NITROXIDES

We have formed adduct radicals (ArCHOMu .) by muonium addition to the carbonyl group of benzaldehyde and its derivatives. The muon coupling is found to be highly sensitive to the nature of substituents in the b enzene ring, being increased by electron releasing groups. Similarly, the N-14 coupling in a series of nitroxides [ArN(O .)OSiEt3], measured using ESR spectroscopy, is increased by electron releasing substituen ts and a linear correlation is found between the two; their connected nature is discussed. For the radical derived from benzaldehyde itself, a strong dependence is also found on the solvent in which it is solve d. We suggest that this may be used in the study of solvent effects, p articularly H-bonding, pertinent to organic and bioorganic media.