**9. The importance and uses of Schiff bases**

Today, with the development of spectral methods, the mechanisms of biochemical reactions can be explained. It has been determined that some reactions in living organisms proceed on Schiff bases, Schiff bases eliminate the toxic effects of aldehyde and amine components and bind free metal ions. The importance of Schiff bases increases day by day as they can be used in biological systems [79], chemical catalysis [80], medicine and pharmacy [81], chemical analysis, and new technologies [82, 83]

**Figure 21.** *Examples of biologically active Schiff bases.*

due to their properties. If we briefly summarize the reasons why Schiff bases have such a wide working area [84]:


In addition, due to their photochromism feature, they can be used in different fields, such as controlling and measuring radiation intensity, image systems, and optical computers [85]. Since the metal complexes of these compounds are colored substances, they are used as pigment dyestuffs in the dye industry, especially in textile dyeing [86, 87]. Moreover, they are widely used in the perfume and pharmaceutical industries. These compounds also have properties, such as synthetic oxygen carrier and intermediate in enzymatic reactions. They are also used as spectrophotometric reagents in analytical chemistry, as they react selectively and specifically to some metal ions. They can be used in aircraft construction, television and computer screens, and digital clock displays by taking advantage of the liquid crystal feature that occurs in some metal complexes [88].
