[joyb]

When resonance raman infrared spectroscopy is used to probe the binding of oxygen to haemoglobin and haemocyanin. The O-O bond stretching vibration had a maximum absorbance of 1122cm^-1 in oxyhaemoglobin and 744cm^-1 in oxyhaemocyanin. What information does this give us about the length of the O-O bond in these two proteins?

(I know to use absorbance to calculate wavelength and thus energy of the photon required to excite the molecule, but I don't understand how this relates to bond length. Please help?)