I prepared a polymer containing benzene ring, C=C group and methoxy group in its structure, when I measured UV absorption of this polymer in chloroform, I obtained three bands. I can not explain the reason of the presence of second band.
Note: I'm sure that, third peak show absorption of C=C group.
Hello dear these will be the wave length for your compound:
benzene: 204 nm
alkene : 177 nm
metoxi: 6 nm
For example if the benzene was modified the absorption will be higher than 204, for example the absorption of the methoxybenzene (anisole) would be 230 nm.
You can calculate the absorption values of your figure depending of your final structure by using the values before mentioned. Please remember that the absorption values will depend on your structure.
Best regards
Dear Amal
Benzene itself has λmax (nm)204 log ε 3.9; λmax (nm) 254 log ε 2.0. For C=C, of H2C=CH2 π→π*160-190, 162. In general, the determination of the absorption values depends on the exact structure that you have. Please, find in attach: Terms used in UV/VIS spectrometry by Richard Koplík. It contain λmax and log ε of enomrous groups and compunds, it might be useful for you.
you should show the chemical structure for better understanding. Also these bands can not be attributed to absorption of substituted groups alone, such as the third band is due to C=C. Best
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