Woodward–Fieser rules, caffeine, absorption maximum, λmax, wavelength

May 2019
6
0
Germany
Hey do any of you know how to calculate the the wavelength of the absorption maximum (λmax) in an ultraviolet–visible spectrum of caffeine using the Woodward–Fieser rules?

Ist Purin base with 3 Methyl groups.
and im using it desolved in water=> so -8 nm

in lit. it is around 275 nm and calculated it should lay at 284 nm (276nm in water)

but i cant quite figure out the method of calcualtion...?:confused:

That would be a great help!

https://en.wikipedia.org/wiki/Woodward's_rules

Woodward–Fieser rules, caffeine, absorption maximum, λmax, wavelength