Four new symmetrical Schiff bases derived from 2,2′-diamino-6,6′-dibromo-4,4′-dimethyl-1,1′-biphenyl or 2,2′-diamino-4,4′-dimethyl-1,1′-biphenyl, and 3,5-dichloro- or 5-nitro-salicylaldehyde, were synthesized and reacted with copper-, iron- and zinc-acetate, producing the corresponding complexes. The Schiff bases and their metal complexes were characterized by ¹H-, ¹³C-NMR, IR and UV-Vis spectroscopy and elemental analysis. The structures of one Schiff base and the two zinc complexes were resolved by X-ray structure determination. Density functional theory (DFT) calculations at the B3LYP/6-31G(d) level of the latter compounds were carried out to optimize and examine their molecular geometries. The biomedical applications of the Schiff bases and their complexes were investigated as anticancer or antimicrobial agents.

A new open-chain ether-linked polymer has been prepared via nucleophilic aromatic substitution reaction on a C-F bond of 1,4-dibromo-2,5-difluorobenzene by using 2,2-bis(4-hydroxyphenyl) hexafluoropropane (bisphenol AF or BAF). The new polymer (PE-AF) has shown a good solubility in non-polar solvents, good thermal stability (up to 300 °C) and random surface morphology. Tailoring these properties has been achieved by utilizing the post-modification synthetic methodology on the bromo-sites of the polymer backbone via the application of an Ullmann coupling reaction with aniline to form the polymer (PE-Sec-NHPh). The successful synthesis of the polymers has been confirmed by elemental analysis, infrared spectroscopy (IR), ¹H- and ¹³C-NMR and ¹³C CP-MAS solid state. Upon incorporation of the aniline linker, the nitrogen content increased when compared with the parent polymer chain, and thus PE-Sec-NHPh revealed a higher thermal stability up to 350 °C and a more uniformly aggregated morphology (spherical particles ca. 0.3–0.1 µm). A further evaluation has been conducted on the polymers by measuring their surface tendency toward carbon dioxide capture. Interestingly, despite their non-porous nature, the polymers demonstrated a reasonable amount of gas capture that reached 90.0 and 41.0 mg/g for PE-Sec-NHPh and PE-AF, respectively. Furthermore, the calculated CO₂ binding affinities of the polymers are consistent with data reported previously in the literature.

The Schiff base ligand 3,5-diiodosalicylideneamino-4,4′-dimethyl-1,1′-biphenyl was synthesized and reacted with manganese, cobalt, iron and copper acetate producing the corresponding complexes, which were characterized by IR, UV-Vis spectroscopy and elemental analysis. The structure of copper complex Cu(II)L was resolved by single crystal X-ray diffraction. The biological efficacy of the Schiff base and the corresponding complexes were examined in their capacity as antimicrobial agents. Density functional theory calculations were carried out to optimize and examine the molecular geometry of Cu(II)L complex.