Synthesis of macrocyclization cyclophanes and their metal complexes, characterization and antimicrobial activity

Abstract

Due to their chemical properties, cyclophane-type compounds constitute an interesting organic chemistry class. In the structure of all cyclic compounds, macrocyclization is the most critical issue for high-efficiency synthesis. Especially with a small cyclophane structure, the experimental steps are more complicated than with a prominent cyclophane structure. In this manuscript, three different material groups were applied to synthesize silver cyclophane compounds for smart drug properties. In the first material group, 5,6-dimetil-1H-benzo[d] imidazole (1) and 2,6-bis(chloromethyl)pyridine (2) were reacted to form 5,6-dimethyl-1- ((6-((5,6-dimethyl-1H-benzo[d]imidazole-1-il)methyl)pyridine-2-il)methyl)-1H-benzo[d] imidazole compound (3). In the second material group, ethyl 2-bromoacetate (4) reacted to different nitrogen atoms of the cyclophane compound to form a symmetric carbene compound, which is water-soluble (5). In the third material group, the silver (I) and palladium (II) metal complexes were synthesized due to the reaction with silver(I) oxide (6) and palladium (II) chloride (7). Antimicrobial activities of the carbene compounds and silver and palladium complexes (5, 6, and 7) were investigated against bacteria and fungal in more detail. Silver (I) complex (6) shows an antimicrobial agent when mixed with microorganisms, such as Gram-positive, Gram-negative, and fungal, but this property has not been observed in the palladium (II)-carbene complex (7).