Abstract
The self-assembly of iron(III) chloride with three pyrazolyl-s-triazine ligands, namely 2,4-bis(3,5-dimethyl-1H-pyrazol-1-yl)-6-(piperidin-1-yl)-1,3,5-triazine ((BPT)-B-Pip), 4-(4,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazin-2-yl)morpholine ((BPT)-B-Morph), and 4,4'-(6-(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazine-2,4-diyl)dimorpholine ((PT)-P-bisMorph) afforded [Fe((BPT)-B-Pip)Cl-2][FeCl4] (1), [Fe((BPT)-B-Morph)Cl-2][FeCl4] (2), and [H((PT)-P-bisMorph)][FeCl4]. (PT)-P-bisMorph.2H(2)O (3), respectively, in good yield. In complexes 1 and 2, the Fe(III) is pentacoordinated with three Fe-N interactions from the pincer ligand and two coordinated chloride anions in the inner sphere, and FeCl4 over bar in the outer sphere. Complex 3 is comprised of one protonated ligand as cationic part, one FeCl4 over bar anion, and one neutral (PT)-P-bisMorph molecule in addition to two crystallized water molecules. Analysis of molecular packing using Hirshfeld calculations indicated that H horizontal ellipsis H and Cl horizontal ellipsis H are the most important in the molecular packing. They comprised 40.1% and 37.4%, respectively in 1 and 32.4% and 37.8%, respectively in 2. Complex 1 exhibited the most bioactivity against the tested microbes while 3 had the lowest bioactivity. The (PT)-P-bisMorph and (BPT)-B-Morph were inactive towards the tested microbes while (BPT)-B-Pip was active. As a whole, the Fe(III) complexes have enhanced antibacterial and antifungal activities as compared to the free ligands.