Synthesis, Characterization, and Antimicrobial Activity of Salisaldehyde‐Based Terpolymeric Ligand and Its Transition Metal Complexes

Abstract

In this study, we first synthesized a salisaldehyde-based terpolymer (SBT) ligand using salisaldehyde and phenylthiourea with glutaraldehyde. We then synthesized SBT metal complexes (SBT-M(II)) with the use of transition metal ions, such as Co(II), Ni(II), Cu(II), and Zn(II). To elucidate the structure and geometry of the metal ions, SBT and SBT-M(II) were characterized by elemental and spectral analysis. SBT-Co(II) and SBT-Ni(II) showed six coordination bonds with two water molecules, whereas SBT-Cu(II) and SBT-Zn(II) showed four coordination bonds. Gel permeation chromatography was used to determine the molecular weight of SBT. The thermal stability of SBT and SBT-M(II) was tested using thermogravimetric and differential thermal analysis. Thermal kinetic parameters such as activation energy and exponential factor were calculated using the Coats-Redfern method. In addition, antibacterial activity of SBT and SBT-M(II) was evaluated against several bacterial and fungal cultures using the agar well diffusion method. The polarity of the metal ion in SBT-M(II) was reduced which might contribute to its superior antimicrobial property. C 2016 Wiley Periodicals, Inc. Adv Polym Technol 201 , , 21689; View this article online at wileyonlinelibrary.com. Experimental MATERIALSSalisaldehyde, phenylthiourea, glutaraldehyde, sodium hydroxide (NaOH), and metal salts were purchased from Sigma