Photochemistry and Photovoltaic Cells

Many organic and inorganic chemical reactions are induced by light. An example of an organic photochemical reaction is the preparation of benzyl chloride (CgHjCH Cl) from toluene (C HjCH ) and chlorine (Cl ). When the diatomic molecule of chlorine is exposed to hght, breakage of the Cl-Cl bond occurs and two chlorine radicals are then formed  

The chlorine radical is then used to convert toluene to the benzyl radical C1 +QHjCH2 QH5CH2 +HC1 

The benzyl radical reacts with the second chlorine radical to form benzyl choride  

Approximately 100,000 tons of benzyl chloride is produced annually using this gas-phase photochemical reaction. 

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