Green Synthesis, Structural Clarification, and Spectral Analysis of Schiff Base Ni(II) and Cu(II) Complexes Based on Pyridines with Associated Biological Significance: Schiff base complexes, pyridine ligands, green synthesis, nickel (II), copper (II), and spectral characterization. jar. 2026;30(1):01-08. doi:10.65540/jar.v30i1.1360