Photochemistry

basci data of phtochemistry

1. TOPIC "Photochemistry" By Dr. Gopalkrushna H. Murhekar

2. Agenda Introduction Quantum yield Experimental determination of quantum yield Jablonski diagram Fluorescence phosphorescence Chemiluminescence Bioluminescence Applications Bibliography

3. Deals with photochemical reactions . Caused by the abosobtion of light radiations from visible and ultraviolet region . INTRODUCTION

4. QUANTUM YIELD To express the efficiency , The number of molecules reacting per quantum energy absorbed . The number of moles reacting per Einstein's of energy absorbed . ɸ = no. of molecules reacting in a given time no. of quanta of light absorbed in the same time ɸ = no. of molecule reacting in a given time no. of Einstein of light absorbed in the same time

5. Experimental D etermination of Quantum Yield Determination of number of moles reacted. Determination of number of Einstein's absorbed. Source of light Monochromator Reaction cell Detector

6. Instrument for Quantum Yield Determination

7. J oblonski Diagram (10 -13 to 10 -12 Sec)

8. Fluorescence The light absorbed may be remitted almost instantaneously in one or more steps this phenomenon is known as fluorescence.

9. Phosphorescence The emission in fluorescence ceases with the removal of source of light, this phenomenon is know as phosphorescence.

10. Chemiluminescence The emission of light in chemical reaction at ordinary temperature is called chemiluminescence . It is just the reverse of photochemical reaction.

11. Bioluminescence Production and emission of light by living organism is called bioluminescence. Bios – Living and Lumen – Light. Is a naturally occurring form of chemiluminescence where energy id released by a chemical reaction in the form of light emission.

12. Carbon Cycle Ozone formation in atmosphere

13. Bibliography