Abstract
A new Ag(I)-azine complex of the formula [Ag(L-a)](2)(ClO4)(2).1/2(L-b) was synthesized and characterized using elemental analysis, FTIR, XPS and single-crystal X-ray diffraction. The [Ag(L-a)](2)(ClO4)(2).1/2(L-b) complex was obtained via Ag(I)-mediated hydrolysis of 2-(((1-(pyridin-2-yl)ethylidene)hydrazineylidene)methyl)phenol (L) with AgClO4 leading to the formation of the azines (1E,2E)-1,2-bis(1-(pyridin-2-yl)ethylidene)hydrazine (L-a) and 2,2'-((1E,1'E)-hydrazine-1,2-diylidene bis(methanylylidene)) diphenol (L-b). The former underwent complexation with AgClO4, while the latter was co-crystallized with the resulting Ag(I) complex, leading to the complex formula [Ag(L-a)](2)(ClO4)(2).1/2(L-b). In this complex, the azine L-a is acting as a bridged bidentate chelate connecting the two Ag(I) sites, leading to a tetra-coordinated Ag(I) with a distorted square planar coordination environment. Hirshfeld analysis indicated the importance of the H horizontal ellipsis H (38.4%), O horizontal ellipsis H (17.9%), H horizontal ellipsis C (13.2%), C horizontal ellipsis C (9.0%) and N horizontal ellipsis H (8.9%) interactions in the molecular packing. The antimicrobial, antioxidant and cytotoxic activities of the [Ag(L-a)](2)(ClO4)(2).1/2(L-b) complex were examined and compared with those of [Ag(L-a)](2)(ClO4)(2). The former was found to have lower bioactivity than the latter, which shed light on the lowering of biological actions as a consequence of the incorporation of the azine L-b within the Ag(I) complex. In other words, lowering the %Ag decreases the biological actions. The [Ag(L-a)](2)(ClO4)(2).1/2(L-b) complex (MIC = 39 mu g/mL) has higher activity against the fungus A. fumigatus than the control Ketoconazole (MIC =156 mu g/mL). This complex also has good cytotoxic activity against colon carcinoma and weak antioxidant activity.