Benzylbenzoin benzyl ethers as new photoinitiators

The title benzoins are prepared and their photochemistry has been investiga ted. Product analysis studies indicate that the benzoin undergoes Norrish T ype I photocleavage to generate benzoyl and benzyloxybenzyl radical, follow ed by thermal fragmentation to produce deoxybenzoin thereby generating benz yl radical. All three transient species are actually detected and character ized by laser hash photolysis of the benzoin in solution at room temperatur e, The efficiency of the benzoins as photoinitiator has been also investiga ted, Effects of ring substituents and polycyclic aromatic rings on the phot oreactivity have been revealed.