Novel family of bis-pyrazole coordination complexes as potent antibacterial and antifungal agents

Abstract

A new pyrazole ligand, N,N-bis(2(1',5,5'-trimethyl-1H,1'H-[3,3'-bipyrazol]-1-yl)ethyl)propan-1-amine (L) was synthesized and characterized by ¹H-NMR, ¹³C-NMR, FT-IR and HRMS. The coordination ability of the ligand has been employed for the construction of a new family of coordination complexes, namely: [Cu₂LCl₄] (1), [ML(CH₃OH)(H₂O)](ClO₄)₂ (M^II = Ni (2), Co (3)) and [FeL(NCS)₂] (4). The series of complexes were characterized using single-crystal X-ray diffraction, HRMS, FT-IR and UV-visible spectroscopy. Moreover, the iron(ii) analogue was investigated by ⁵⁷Fe Mössbauer spectroscopy and SQUID magnetometry. Single-crystal X-ray structures of the prepared complexes are debated within the framework of the cooperative effect of the hydrogen bonding network and counter anions on the supramolecular formations observed. Furthermore, within the context of biological activity surveys, these compounds were reviewed against different types of bacteria to validate their efficiency, including both Gram-positive as well as Gram-negative bacteria. Enhanced behaviour towards Fusarium oxysporum f. sp. albedinis fungi, were detected for 1 and 4.