Spectroscopy of EDA Complexes at High Pressures. VI. Absorption and Fluorescence of Crystalline TNB and TNF Complexes

Several aromatic hydrocarbons are complexed with trinitrobenzene (TNB) and trinitrofluorenone (TNF) in the crystalline state and subjected to increasing pressures (0-30 kbar). The charge transfer absorption shows a ∼1200 cm−1 red shift, while the fluorescence red shift may vary between 200-1700 cm−1 at 25 kbar. In the same complexes the Stokes shift decreases at higher pressures. This decrease can be understood in terms of charge-transfer forces and potential energy curves appropriate for weak EDA complexes.