Summary The ultraviolet absorption spectrum of p-methylisopropenylbenzene resembles that of styrene while the spectrum of the ortho isomer does not have the expected maximum near 250 mp. This difference can be accounted for on the basis that in the ortho compound there is steric interference with the resonance between the benzene ring and the olefinic group in the side chain. A similar conclusion is reached by comparison of the infrared ...
