Research of the synthesis, structural characterization and biological activities of mixed ligand complexes containing aniscic acid nicotinamide/N,N'-diethylnicointinamide/1,10-phenathroline ligands of some transition metal cations

Anisic acid (p-methoxybenzoic acid) was first synthesized in 1841 by French chemist and scientist Auguste Cahours through the oxidation of anethole (C10H12O). Anethole is an essential oil found as an active ingredient in anise. The anisic acid synthesized by Cahours was purified from anise extract by recrystallization using diluted nitric acid. Anisic acid is also referred to as p-methoxybenzoic acid or sometimes dragonic acid. Anisic acid is frequently used in the pharmaceutical industry as a raw material for drugs, as a flavoring and preservative in the food industry, as a preservative in the cosmetic industry due to its antimicrobial properties, and in the fragrance and plastic industries. Moreover, anisic acid, being an important intermediate in organic chemistry, is used as a starting material in various reactions due to its methoxy group and carboxylic acid group. These broad applications make anisic acid an important compound in both industrial chemistry and consumer products. In this thesis study, a total of 14 mixed-ligand complexes containing Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) transition metals, along with p-methoxybenzoic acid and the ligands nicotinamide (NA)/N,N-diethylnicotinamide (DENA)/1,10-phenanthroline (PHEN), were synthesized for the first time. The molecular formulas of the synthesized complexes are proposed as follows: [Mn(C8H7O3)2(C6H6N2O)2(H2O] (I) [Co(C8H7O3)2(C6H6N2O)2(H2O)2].H2O (II) [Ni(C8H7O3)2(C6H6N2O)2(H2O)2] (III) [Cu(C8H7O3)2(C6H6N2O)2(H2O)] (IV) [Zn(C8H7O3)2(C6H6N2O)2(H2O)2] (V) [Mn(C8H7O3)2(C10H14N2O)2(H2O)2] (VI) [Co(C8H7O3)2(C10H14N2O)2(H2O)2].2H2O (VII) [Ni(C8H7O3)2(C10H14N2O)2(H2O)2] (VIII) [Cu(C8H7O3)2(C10H14N2O)2(H2O)] (IX) [Zn(C8H7O3)2(C10H14N2O)2(H2O)2].H2O (X) [Co(C8H7O3)2(C12H8N2)].H2O (XI) [Ni(C8H7O3)2(C12H8N2)].H2O (XII) [Cu(C8H7O3)2(C12H8N2)(H2O)].2H2O (XIII) [Zn(C8H7O3)2(C12H8N2)(H2O)] (XIV) The structures of the synthesized complexes were analyzed by elemental analysis, FT-IR spectroscopy, single crystal X-ray diffraction diffractometry, magnetic susceptibility and melting point determination methods. Thermal analysis (TGA/DTA/DrTGA) methods were also used for the characterization of thermal decomposition behaviors of the molecules. Finally, the biological activities of the complex molecules whose structures were characterized were investigated in cell culture medium.