الفهرس | Only 14 pages are availabe for public view |
Abstract Our interest i directed towards tudying the photochemical and pbotophy ical propertie of some heterocyclic compound . $0 yntbe is of some coumarin derivariv s. 7-hydroxyc .lunar in \ as used a a rtarting mat rial to synthe is 7-allyloxycoumarin dye II. 7-propargyloxycQumarin dye ill. Dye Twa reacted with nitrilimines [0 give the cycloadducr dyes IVlL~’ The effect of olvenrs On the light ab orption and fluorescence emis ion of d, e II, III also 011 th - eycloaddu dyes IV,..., were discussed. It v a’ found that the effect of solvent polarity on the ab orption trausirion energy, half-band width v 1’_ and oscillator strength (f), displayed different spectral behaviour i.e, positive or negative . olvatochromism in different solvent classes, Stoke .hifts. fluorescence energie and fluorescence quantum ield tJlr also have been tudied . .Furthermore, the effect of temperature on excitation and fluorescence spectra of dye I b wa discu sed according to Williams. Lande! and Ferry (VlLF) equation, TI1e re ult revealed that both of excitation and fluore cenee spe tra of tbe dye abe, \VLFequatiotl at remperatur ranged from Tg to (Tg + lOOcC), while at temperature higher than (Tg + 100” ) another beha iour was obser ed. The effect of concentration on the Onere ’eeoc pectra of dye n lind IVb [0 know the probability of fonnatiou of the excimer Or higher aggregation in the excited tale Was tudied, The results showed that there. |