C-O (carbonlyl) peaks occur usually around 1500-1700. I Cant clearly see the picture but I would say you have at least 1-2 Carbonly groups, since there are 2 peaks that occur past 1500. Solution C-O (carbonlyl) peaks occur usually around 1500-1700. I Cant clearly see the picture but I would say you have at least 1-2 Carbonly groups, since there are 2 peaks that occur past 1500..