Abstract
The self‐assembled [Ag (PTDM)NO3] (1), [Ag (PTDM)2(H2O)]ClO4.H2O (2) and [Ag5(PTDM)4(H2O)6(ClO4)4]ClO4.2H2O (3) complexes were synthesized by the direct mixing of AgX (X = NO3¯ or ClO4¯) and 4,4′‐[6‐(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)‐1,3,5‐triazine‐2,4‐diyl]dimorpholine (PTDM) ligand in water–methanol mixture. The coordination numbers of silver range from three to five. Complex 3 is a rare case in which one nitrogen atom from the same s‐triazine core of the PTDM ligand has a μ(1,1) bridging mode between Ag1 and Ag2 in the penta‐nuclear array with Ag1–N1 and Ag2–N1 distances of 2.666(4) and 2.418(3) Å, respectively. Its 3D topology has a kind of primitive dense packing derived from the α‐Po type structure. Hirshfeld analysis showed that the percentages of the O…H hydrogen bonds were 32.4, 25.4, and 42.0% in complexes 1–3, respectively. While the ligand showed no antimicrobial activity at the applicable concentration, the penta‐nuclear complex 3 had higher antibacterial (MIC = 3.7 μmol/L) and antifungal (14.6 μmol/L) potencies toward the tested microbes compared with complexes 1 and 2. Also, the killing doses of 3 were in the range of 7.3–58.5 μmol/L compared with 18.2–291.1 and 20.1–160.6 μmol/L for 1 and 2, respectively. It is clear that the higher Ag‐content in 3 could be the main reason for its higher antimicrobial activity.
Three Ag(I)‐pyrazolyl‐s‐triazine complexes were synthesized and well characterized. The antimicrobial profile of the studied complexes depend on the Ag‐content where increasing the Ag‐content significantly enhanced the antimicrobial activity.