Aromatics ring breathing modes

Spectra 2a is a MIR spectra of the unexposed IPS that contained light stabilizers. Note the intense aromatic ring breathing modes between approximately 1600 cm and 1400 cm (2). 

Raman spectra obtained on concentrated protein solutions (ca. 20 mM) are dominated by contributions from the repeating amide group of the polypeptide backbone and from the sldechalns of aromatic amino acids (6). Phenylalanine and tryptophan exhibit particularly Intense ring breathing modes at 1006 and 1014 cm, respectively. An additional strong peak due to tryptophan Is typically observed at 760 cm ... 

The amide 1 peak is relatively weak in the Raman spectrum, and the amide II peak is not observed. At the low-frequency side of the amide I peak, weak features of DNA and RNA may be observed for the nuclei and nucleoli. All cellular regions show distinct methyl and methylene deformation vibrations at about 1450cm" , and broad, intense amide 111 vibrations between 1350 and 1220cm" . At around 1000 cm" , the symmetric ring breathing mode of the aromatic phenyl alanine side... 

Spectra Ic corresponds to Photo Ic. No e the intense development of a carbonyl band around 1620 cm. After six months outdoor weathering the peaks related to the aromatic skeletal ring breathing mode have been masked. 

Spectra 2c corresponds to Photo 2c. A significant carbonyl peak has formed, but the aromatic skeletal ring breathing mode peaks are still quite apparent. 

Heterocyclic rings which have two double bonds in a five-membered ring are all aromatic in character and show typical ring-breathing modes and hydrogen deformations. All those molecules for which a detailed vibrational analysis is available show one... 

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