Water‐Soluble Silver Coordination Polymers Constructed From Bridging Pyrazine Ligands: Syntheses, X‐Ray Structures, Anticancer, and Antimicrobial Investigations

Abstract

ABSTRACT Two novel polymeric complexes were synthesized from the reaction of AgClO 4 with 3‐amino‐6‐(chloromethyl)‐2‐pyrazinecarbonitrile 4‐oxide ( L1‐Cl ) or 3‐aminopyrazine‐2‐carboxylic acid ( HL2 ) to give [Ag(L1‐OCH 3 )( μ ‐OClO 3 )] n ; ( 1 ) or [Ag (HL2)(OClO 3 )] n .nH 2 O ; ( 2 ), respectively. 3‐Amino‐6‐(methoxymethyl)‐2‐pyrazinecarbonitrile 4‐oxide ( L1‐OCH 3 ) is formed by the etherification process that occurred during the synthesis of complex 1 . The complexes architectures were investigated by single‐crystal XRD (SC‐XRD). Both complexes have novel and different polymeric forms based on the pyrazine moiety that adopt a bridging mode between the Ag(I) sites with the difference of donor atoms in each complex. The silver(I) centers in the polymeric chain of complex 1 are connected to one another through the bridging pyrazine ligand and perchlorate anions in an alternative manner. In complex 2 , HL2 does not only act as a linker between the silver centers but also as a bidentate ligand. Hirshfeld surface analysis demonstrated the importance of H···O contacts in the supramolecular structures of 1 (41.7%) and 2 (30.2%). Biological investigations indicated promising antimicrobial and anticancer properties of these water‐soluble complexes. Particularly, complex 1 displays interesting activity against A‐549 (IC 50 = 10.53 ± 0.44 𝜇 M) and MCF‐7 (IC 50 = 8.41 ± 0.31 𝜇 M) cell lines when contrasted to cis ‐platin. Regarding antibacterial action, the most promising MIC value and inhibition zone diameter are 8 μ g/mL and 20 mm, respectively, for 1 against B. subtilis .