Synthesis, Crystal Structure, DFT, Hirshfeld Analysis, and Molecular Docking Studies of s ‐Triazine‐Based Hg(II) Complexes as Promising Antimicrobial Candidates
Raghdaa A. Massoud, Ayman El‐Faham, Saied M. Soliman, Assem Barakat, Matti Haukka, Sherif Ramadan, Eman Hassan Elsayed, Sara M. KhattabABSTRACT
Three heteroleptic Hg(II) complexes—[Hg(PBMT)Cl 2 ] ( 1 ), [Hg(MBPT)Cl 2 ] ( 2 ), and [Hg(MBPT)Br 2 ] ( 3 )—were synthesized. The ligands 4,4′‐(6‐(3,5‐Dimethyl‐1 H ‐pyrazol‐1‐yl)‐1,3,5‐triazine‐2,4‐diyl)dimorpholine ( PBMT) and 2,4‐ bis (3,5‐dimethyl‐1 H ‐pyrazol‐1‐yl)‐6‐methoxy‐1,3,5‐triazine ( MBPT) act as bidentate and tridentate chelates, respectively. 1 features a distorted tetrahedral Hg(II) ( τ 4 = 0.705), while 2 and 3 have distorted square pyramidal geometry ( τ 5 = 0.15 for 2 ). Hirshfeld surface analysis reveals H⋯H interactions as the dominant crystal packing forces (46.3% for 1 , 36.4% for 2 ). Complex 1 exhibits the strongest ligand‐to‐metal charge transfer, reflecting higher metal‐ligand bond covalency. Nonlinear optical (NLO) calculations show that 3 possesses promising hyperpolarizability values, suggesting potential for optoelectronic applications. Antimicrobial testing revealed that 1 is highly effective against Staphylococcus aureus with minimum inhibitory concentration (MIC) of 4.8 µg/mL while 2 demonstrated superior antifungal activity against A. fumigatus (MIC = 4.8 µg/mL), outperforming ketoconazole. Molecular docking studies confirm that 1 has the highest binding affinity, correlating with its strong antimicrobial activity through stable active‐site interactions.