[gralla55]

Not sure if this is the right section for this type of question, but anyway: I'm supposed to mach the compounds with the correct IR-graphs. There are four compounds and only three graphs, so I guess one of the compounds are without a graph.

Now, I think graph nr 1 has to be for compound b, since that one is the only graph without a C=C peak at 1680-1620cm-1. But I have no idea how to figure out the other two. In one graph the C=O peak is shiftet slightly to the right, which should mean something at least. Would appreciate any *delete me*

[research]

I think the one which show C=O in 1725cm^-1 should represent compound d because in this compound there is resonance with C=O so this phenomenon can decrease the amount of vibration but in the other IR spectrum this isn't seen.