Synthesis, Characterization, and BSA-Binding Studies of Novel Sulfonated Zinc-Triazine Complexes.

Four Zn(II) complexes containing a pyridyl triazine core (L1 = 3-(2-pyridyl)-5,6-di(2-furyl)-1,2,4-triazine-5',5″-disulfonic acid disodium salt and L2 = 3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine-4',4″-disulfonic acid sodium salt) were synthesized, and their chemical formulas were finalized as [Zn(L1)Cl2]·5H2O·ZnCl2 (1), [Zn(L1)2Cl2]·4H2O·2CH3OH (2), [Zn(L2)Cl2]·3H2O·CH3OH (3), and [Zn(L2)2Cl2] (4). The synthesized complexes are water soluble, making them good candidates for biological applications. All four complexes have been characterized by elemental analysis and 1H NMR, IR, and UV-Vis spectroscopy. The IR stretching frequency of N=N and C=N bonds of complexes 1-4 have shifted to lower frequencies in comparison with free ligands, and a bathochromic shift was observed in UV-Vis spectra of all four complexes. The binding studies of ligands and complexes 1-4 with bovine serum albumin (BSA) resulted binding constants (Kb) of 3.09 × 104 M-1, 12.30 × 104 M-1, and 16.84 × 104 M-1 for ferene, complex 1, and complex 2, respectively, indicating potent serum distribution via albumins.