The following FTIR spectrum shows the absorbance band of the carbonyl group (C=O) of 4 ester molecules. Compare the purple and the blue curves?
Answers
Answer:
Your carbonyl band has at least two bands heavily overlapped. Your picture is so blurred and I cannot read the frequency. So, this is a guess of the frequency. The strongest peak is at 1715 cm-1, which is the non-hydrogen bonded carbonyl group. The weak band is at 1685 cm-1, which is hydrogen bonded carbonyl band. Both purple and blue spectra have these bands with different intensities. If you have a deconvolution software, you will be resolve these two bands and measure more accurate intensities. Upon drying, the amount of water that is the source of hydrogen bonding decreases and thus the 1685 cm-1 band shifts to higher frequency at 1715 cm-1. Accordingly, the band at 1715 cm-1 shows higher intensity (purpose) upon drying.
Your carbonyl band has at least two bands heavily overlapped. Your picture is so blurred and I cannot read the frequency. So, this is a guess of the frequency. The strongest peak is at 1715 cm-1, which is the non-hydrogen bonded carbonyl group. The weak band is at 1685 cm-1, which is hydrogen bonded carbonyl band. Both purple and blue spectra have these bands with different intensities. If you have a deconvolution software, you will be resolve these two bands and measure more accurate intensities. Upon drying, the amount of water that is the source of hydrogen bonding decreases and thus the 1685 cm-1 band shifts to higher frequency at 1715 cm-1. Accordingly, the band at 1715 cm-1 shows higher intensity (purpose) upon drying.