Abstract
The overall efficiency of energy transfer can be a function of electronic and orientational properties of sensitizer and acceptor, and of the efficiency of processes which compete with energy transfer in donor and acceptor. The mechanistic characteristics of the photocycloaddition of isophorone to 1,1 -di-methoxyethylene lend themselves to an analysis of the efficiency of energy transfer from substituted benzophenones and acetophenones to isophorone.