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)Cl(2)]·5H(2)O·ZnCl(2) (1), [Zn(L1)(2)Cl(2)]·4H(2)O·2CH(3)OH (2), [Zn(L2)Cl(2)]·3H(2)O·CH(3)OH (3), and [Zn(L2)(2)Cl(2)] (4). The synthesized complexes are water soluble, making them good candidates for biological applications. All four complexes have been characterized by elemental analysis and (1)H 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 (K (b)) of 3.09 × 10(4) M(−1), 12.30 × 10(4) M(−1), and 16.84 × 10(4) M(−1) for ferene, complex 1, and complex 2, respectively, indicating potent serum distribution via albumins.