Electronic Transitions in Phenylboronic Acids. I. Substituent and Solvent Effects

摘要

The singlet La transition of substituted phenyl boronic acids unexpectedly shifts to higher energy with a solvent change from hexane to water or acetonitrile. This is the result of substantial charge transfer character in the singlet La transition. The singlet La transition energies of p-RC6H4B(OH)2 and p-RC6H4CHO exhibit a linear correlation with mass spectroscopic appearance potentials of RCH2(+). The singlet La transition is discussed in terms of simple molecular orbital calculations. (Author)