New polymeric Schiff base and its metal complexes

Abstract

A novel polymeric Schiff base was synthesized by the reaction of a Schiff base from 2,4-dihydroxy benzaldehyde and aniline with acryloyl chloride and was polymerized in methyl ethyl ketone at 70°C with benzoyl peroxide as a free-radical initiator. Polychelates were obtained in an alkaline solution of poly(2-hydroxy-4-acryloyloxy-N-phenylbenzylidine) with aqueous solutions of metal ions such as Cu(II), Ni(II), Co(II), Ca(II), Cd(II), Mn(II), and Zn(II). The polymeric Schiff base and polychelates were characterized with elemental analysis and spectral studies. The elemental analysis of the polychelates suggested that the metal-to-ligand ratio was 1:2. The IR spectral data of the polychelates indicated that the metals were coordinated through the nitrogen and oxygen of the phenolic OOH group. Diffuse reflectance spectra, electron paramagnetic resonance, and magnetic moment studies revealed that the polychelates of the Cu(II) complex were squareplanar, those of the Ni(II), Mn(II), and Co(II) complexes were octahedral, and those of the Ca(II), Cd(II), and Zn(II) complexes were tetrahedral. X-ray diffraction studies revealed that the polychelates were highly crystalline. The thermal properties of the Schiff base and polychelates were also examined.

Synthesis, physicochemical investigation and biological studies of Zinc(II) complexes with 1,2,4-triazole Schiff bases

“…All the complexes are insoluble in water and fusible at higher temperatures and are polymeric in nature [42,43].…”

Studies of new oligomer–metal complexes and their antibacterial activities

“…It is found that the E a values parallel the thermal stability. The negative value obtained for the entropy change (Δ S ) and the low value of frequency factor ( Z ) suggest that both the oligomeric ligand and its metal complexes undergo a slow degradation reaction , . The order of the reaction for all the compounds is nearly one.…”

“…The oligomer–metal complexes have a more close‐packed structure than the ligand. Generally, insertion of metal ions into a polymeric lattice increases the crystallinity . The appearance of increased crystallinity in the case of the metal complexes may be due to the inherent crystalline nature of the metals.…”

On the Electrical and Optical Properties of Some Poly(Azomethine Sulfone)s in Thin Films

“…[17][18][19] Another interesting property of these polymeric materials is their complex-forming ability with transition metal ions, exhibiting a wide variation in electrical and magnetic characteristics. [20,21] Some of polyazomethines exhibit thermotropic liquid crystal behavior [15,22] due to having mainly azomethine linkages in the backbone and they can be used to obtain high performances fibers. [23] However these materials have some drawbacks (or advantages depending on the type of applications) such as low solubility in organic solvents and high melting temperatures.…”