The ultraviolet absorption maxima and molar refractions of positional isomeric methyl-and dimethylstyrenes are consistent with the concepts of steric hindrance, resonance and induction. For example, the absorption maxima and exaltations of the methylstyrenes stand in the order para> meta> ortho. Among the dimethylstyrenes, the 2, 6-isomer absorbs at the shortest wave length, owing to steric inhibition of resonance, and the 3, 5-isomer absorbs ...
