Schiff base macromolecules have been successfully synthesized, utilizing a classical chemistry route and a dielectric barrier discharge (DBD) plasma technique. The synthesis of monomeric units has been accomplished through typical reactions of aldehyde and amine functional molecules. The condensation polymerization of the Schiff base molecules has been instigated chemically, using p-toluene sulfonyl chloride in refluxed ethanol. The molecular weight of the obtained polymers was discovered to be 524,664 and 1,503,228 for polymers 4a and 4b, respectively. Additionally, the polymerization reactions were prompted, employing a Dielectric Barrier Discharge (DBD) atmospheric pressure air plasma technique. The DBD plasma demonstrated a very powerful routine to produce high molecular weights macromolecules, which could be an ecofriendly strategy to acquire this class of materials. Moreover, the complexation of polymer 4b with various metal moieties, Ru (II), Co (II), Cu (II), and Ni (II), has been executed in order to have a comparative study of their antitumor activity against MCF-7, A-549, HCT-116, and HepG-2 cell lines. Furthermore, the density functional theory was exploited to optimize the polymers and their complexes, and their HOMO-LUMO and energy gap were calculated, which was utilized to examine the inter/intra molecular charge transfer. The molecular electrostatic potential map was similarly quantified to investigate the reactive sites that are present in the investigated molecules. The result for the docking study confirmed that these complexed polymers adopted numerous important interactions with the amino acid of the targeted enzyme.