Synthesis, structure, electrochemical and antimicrobial properties of N,N′-bis(ferrocenylmethyl)imidazolinium salts

Abstract

The N,N′-bis(ferrocenylmethyl)imidazolinium chloride (3) and bromide (4) were prepared by reaction of N,N’-bis(ferrocenylmethyl)ethylenediamine (2) with NH4X (X=Cl, Br). The N,N′-bis(ferrocenylmethyl)imidazolinium tetrafluoroborate (6) was obtained in two steps from compound (2). The first step involves the synthesis of N,N′-bis(ferrocenylmethyl)imidazolidine (5) by condensation of (2) with aqueous formaldehyde. Compound (5) was successfully converted to the N,N′-bis(ferrocenylmethyl)imidazolinium tetrafluoroborate (6) by treatment with tritylium tetrafluoroborate. The new compounds were characterized by 1H and 13C NMR, IR and elemental analysis techniques which support the proposed structures. The X-ray crystal structure of the N,N′-bis(ferrocenylmethyl)imidazolidine (5) shows two ferrocenyl moieties bridged by an imidazolidine ring. The electrochemical properties were determined by cyclic voltammetry for all compounds. The compounds were screened for their in vitro antimicrobial activities against the Gram-positive, Gram-negative bacteria and antifungal activity against a Candida albicans. (3), (4), (6) show significant antimicrobial activity and theirs MIC values ranged from 169 to 520μg/mL.