Spectroscopy of EDA Complexes at High Pressures. IV. Absorption of Several Haloquinone Complexes in Polymer Matrices

Several haloquinone complexes are subjected to high pressures (0–20 kbar), and the resulting effects are registered in the charge-transfer (CT) absorption spectra. The observed shift in the CT band maxima are discussed in terms of the various interaction terms, including CT forces, which contribute to the displacement of the ground relative to the excited CT state of the EDA complex. The results indicate that the stronger complexes show the smaller red shift or even a blue shift in this pressure range. CT intensities in the 1–20-kbar interval are observed to change by −15% to +40% in this group of related complexes.