Synthesis, physicochemical studies and potential applications of high-molecular-weight ferrocene-based poly(azomethine)ester and its soluble terpolymers

Abstract

A new ferrocene-based poly(azomethine)ester (P) was synthesized via solution polycondensation of 1,1′-di(chlorocarboxyl) ferrocene with a novel preformed 4-((4-(4-(4-hydroxybenzylideneamino)phenoxy)phenylimino)methyl)phenol (SB). The condensation copolymers with good solubility were obtained using commercially available aliphatic (1,3-propan-diol, 1,6-hexan-diol and poly(dimethylsiloxane), hydroxyl-terminated (n = 550)) and aromatic ((1,1,1,3,3,3-hexaflouro)bisphenol propane and bisphenol A) along with the synthesized monomer (SB) and 1,1′-di(chlorocarboxyl) ferrocene. The obtained compounds were characterized by elemental analysis, FTIR and 1H NMR spectrophotometric techniques. The structure–property relation was studied in term of solubility measurements, WAXRD and UV–visible spectroscopic techniques. Average molecular weights, Mw obtained by laser light scattering method were found to be of the order 105 g/mol. Thermogravimetric curves along with polarized optical micrographs were also recorded. SEM–EDX and AFM techniques were employed to study the surface morphology of the synthesized material. Whereas the redox properties were explored using cyclic voltammetric investigations. The biological activity of the synthesized material was studied by utilizing various biological assays (antibacterical, brine shrimp cytotoxicity, antitumor potato disc, DPPH free radical scavenging and free radical induced oxidative DNA damage analysis). In case of brine shrimp (Artemia salina) lethality assay PSi and PF showed LD50 < 1 ppm indicating highly toxic behavior. PF resulted IC50 = 37.78 in tumor inhibition assay. The Schiff base (SB) was highly antioxidant with IC50 = 2.05 ppm and fully protected the plasmid DNA from damage. All the compounds studied were found potent antioxidants, highly cytotoxic and more importantly DNA protecting. The influence of aromatic and aliphatic segments on the properties of organometallic poly(azomethine)ester is discussed.