THE MIGRATION (SPECTROSCOPIC) MOMENT AND THE 'SATURATION EFFECT'. ULTRAVIOLET BAND RE-ASSIGNMENT FOR ANILINE AND ITS DERIVATIVES.
Technical scientific note,
CONSEJO SUPERIOR DE INVESTIGACIONES CIENTIFICAS BARCELONA (SPAIN) DEPARTAMENTO DE QUIMICA ORGANICA
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It is shown that the current band assignment of the ultraviolet absorption spectrum for anilines and derivatives Klevens and Platt is erroneous. The evidence afforded, which include different aspects of the analysis of the absorptivities or oscillator strengths migration moment, saturation effect and halfwidth, show that the 300 millimicron band is related to the singlet-A1g to singlet-B2u singlet-A to singlet-Lb secondary band transition. The data for the substituted anilines allow to expand the study of the saturation effect of the secondary band initia in a preceding report. The evidence afforded seems to indicate that such effect depends mainly upon the resultant migration moment, and also upon the pi-electron density about the benzene nucleus and the polarizabilities of the substituents. It is shown that the evidence afforded by Goodman and Frolen concerning the participation of d-orbitals of bromine in p-bromoanisole is inconclusive. Author
- Organic Chemistry