[CopperSmurf]

I don't see how one can deduce the structure of a compound from a UV/Vis spectrum when it's colored. For example, I could just pick out numbers from the peaks in the spectrum that has X cm^-1 with an extinction coefficient. How is this even useful? How can I even use this to deduce the structure when applied to inorganic complexes? The only thing remotely possible I can think of is to find the energy gaps of delta_octahedral or delta_tetrahedral for high/low spins.

Ex. if I say that I had some sort of complex with a "broad peak" at 13000 cm^-1 with an extinction coefficient of 5 L/(mol cm), what should I know?

[marquis]

Only in relatively rare cases can UV/VIS be used to determine a structure.

Having said that, lets go a little further.  Typically, when you are analyzing a solution by UV/VIS, you have a general idea of the ingredients.  You have a solution that may contain phenols.  Phenols typically absorb at 280 nm.  You run the uv vis and find there is no peak in the 280 nm range.  It's a good bet that no phenols are present.

Another example.  I have an unknown, and it shows a peak in the UV/VIS at 280 nm. The first ingredients I'll investigate are phenols.  It's not proof a phenol is present, but it gives a good hint.   

[CopperSmurf]

sounds like it can turn into a nasty puzzle... thanks for the reply