ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 40, Number 2
JKCSEZ 40(2)
April 20, 1996 

The PPP-MO method has been used to calculate the π electronic excitation energy of fluorane dyes. A good correlation between the absorbed and calculated values for the π→π* transition was found for fluorane dyes. The effect of substituents on the color of fluorane dye was studied on the basis of these calculated results, i.e. HOMO-LUMO energy levels and π-electron-density changes accompanying the first excitation.