Resumen de Predicting the Shifts of Absorption Maxima of Azulene Derivatives Using Molecular Modeling and ZINDO CI Calculations of UV Vis Spectra.

Wyona C. Patalinghug, Maharlika Chang, Joanne Solis

• The deep blue color of azulene is drastically changed by the addition of substituents such as CH3, F, or CHO. Computational semiempirical methods using ZINDO CI are used to model azulene and azulene derivatives and to calculate their UV�vis spectra. The calculated spectra are used to show the trends in absorption band shifts upon addition of electron-donating or electron-withdrawing groups at various carbon positions in azulene. The shifts of the absorption peaks may be predicted using the shapes of the HOMO, LUMO, and LUMO+1 of azulene, a non-alternant hydrocarbon. The predicted shifts of the absorption peaks are compared with those calculated by ZINDO CI.