Electronic structure and geometry of bisperi-tetraphenylnaphthalene

In order to understand the origin of the surprising bathochromic shift produced by phenyl groups in bis peri -tetraphenylnaphthalene both experimental and theoretical methods were used. The geometry of the molecule was determined by means of X-ray diffraction. Absorption, fluorescence and phosphorescence spectra were also analyzed. The epr signal of the triplet state was studied in order to obtain an indication of the distribution of the spin density for that state. Finally electronic wave functions were constructed. It is shown that both electron delocalization and energy delocalization play important roles in the spectroscopic behaviour of bis peri -tetraphenylnaphthalene.