INTERPRETATION OF SPECTROSCOPIC CHANGES UPON ADDUCT FORMATION AND THEIR USE TO DETERMINE E-PARAMETER AND C-PARAMETER

Spectroscopic probes have been examined to determine whether the spectral shifts accompanying adduct formation are dominated by donor-acceptor interactions. New spectral acceptors which employ IR, NMR, or visible spectral shifts are established. Since the C(A)*/E(A)* ratios for these spectral probes differ from those of acceptors whose spectral response is the change of their OH stretching frequency, these new spectral correlations greatly simplify the addition of new donors to the E and C database. Several spectral acceptors, reported to be useful indicators of donor strength, are shown to be insensitive to, or not dominated by, donor-acceptor interactions.