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

Four Zn(II) complexes containing a pyridyl triazine core ( L 1 = 3-(2-pyridyl)-5,6-di(2-furyl)-1,2,4-triazine-5',5″-disulfonic acid disodium salt and L 2 = 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 ]·5H2 O·ZnCl2 ( 1 ), [Zn(L1)2 Cl2 ]·4H2 O·2CH3 OH ( 2 ), [Zn(L2)Cl2 ]·3H2 O·CH3 OH ( 3 ), and [Zn(L2)2 Cl2 ] ( 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 × 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.