Figure 2: Raman spectra of Bisoprolol, Atenolol, Metoprolol, and Propranolol using a 785 nm excitation wavelength. The rectangles indicate the bands assigned to similar vibrations in Atenolol, Bisoprolol, and Metoprolol and the naphthyl group vibrations in Propranolol. The spectra were normalized for comparison.