The wavelength value of the
absorption maximum
and the
molar absorbtivity
are determined by the degree of
Conjugatation
of
p
-
bonds
Absorption maxima : The importance of conjugation
Increasing the number of double bonds shifts the absorption to lower energy
molar absorbtivity
Wavelength nm
N=5
5 pi-bonds, 10 electrons
N=4
4 pi-bonds, 8 electrons
N=3
3 pi-bonds, 6 electrons
GM
Conjugation