Fluorescence Spectroscopy of Some Organic Molecules

Coumarins are the derivatives of 1, 2 benzo pyrone and are well known laserdyes for the blue-green region. These molecules show strong polaritydependent Stokes shift, large changes in dipole moments on excitation, and very highfluorescence quantum yield. Photophysical properties of coumarin dyes have been investigated quite extensively over many years and they have variety of applications viz., biological and chemical sensors, fluorescent probes, fluorescent indicator, sun burn prevention, estimation of enzymes and laser dyes, perfumes, flavourings, anticoagulants androdent poison. Because of the wide spread applications of coumarin derivatives in various fields, we have chosen four newly synthesized coumarin derivatives along with readily available Lumefantrine, the anti-malarial drug viz., for the present study. These coumarin derivatives have been an important class of oxygenatedtriheterocycles, which have been investigated for their anti-inflammatory and anti-microbial activities, whereas, Lumefantrine is used in the treatment of malaria.