Coordination Polymers Containing 1,3-Phenylenebis-((1H-1,2,4-triazol-1-yl)methanone) Ligand: Synthesis and ε-Caprolactone Polymerization Behavior

Abstract

The reaction of isophthaloyl dichloride with 1H-1,2,4-triazole afforded the new ligand 1,3-phenylenebis(1,2,4-triazole-1-yl)methanone (1). A series of Co(II), Cu(II), Zn(II) and Ni(II) complexes were synthesized using 1 and then characterized by melting point analysis, elemental analysis, theoretical calculations, thermogravimetric analysis, X-ray powder diffraction, nuclear magnetic resonance, infrared and Raman spectroscopy. Experimental and computational studies predict the formation of coordination polymers (CPs). The cobalt and copper CPs and zinc(II) complex were found to be good initiators for the ring-opening polymerization of ε-caprolactone (CL) under solvent-free conditions. 1H-NMR analysis showed that the obtained polymers of CL were mainly linear and had terminal hydroxymethylene groups. Differential scanning calorimetry showed that the obtained polycaprolactones had high crystallinity, and TGA showed that they had decomposition temperatures above 400 °C. These results provide insight and guidance for the design of metal complexes with potential applications in the polymerization of CL.

Polymers of ε-Caprolactone Using New Copper(II) and Zinc(II) Complexes as Initiators: Synthesis, Characterization and X-Ray Crystal Structures

“…Therefore, these polymers could be applied or implemented in the design of biodegradable packaging [42]. In general, the PCLs obtained showed a lower dispersion, a higher molecular weight and high degrees of crystallinity compared with other polycaprolactones obtained using previously reported metal catalysts by the authors’ research group and PCLs that are commercially available [9,10,13,16,42].…”

“…It has been reported that ancillary ligands can modify metal complexes that then favor the polymerization of lactones [12,13]. In some cases, pyrazolyl, triazole, and pyrazole derivatives act as nitrogen-donor ligands and therefore increase the Lewis acidity of the metal to enhance the coordination to the lactone [14,15,16]. Specifically, the combination of nitrogen- and oxygen-donor ligands produce active Zn(II) and Cu(II) complexes for the ROP of ε-caprolactone [13,17].…”

Synthesis, Characterization, and Dielectric Behaviors of 4-Diethanolaminomethyl Styrene and Benzyl Methacrylate Copolymer and Its Metal Complexes

“…While the C�O peak in the ligand was seen at 1731 cm −1 , these bonds in the Co(II), Ni(II), and Zn(II) metal complexes were observed at 1723, 1727, and 1723 cm −1 , respectively. ese bands, depending on the formation of the complexes, have shifted to a lower wave number, whereby those results indicated the lower rigidity of the C�O bands in the ligand [25]. e change in the color of the complexes was caused by the orbital transition, namely, the change in the energy of the orbitals, which pointed out that metal complexes were formed.…”

Biological Activity of Complexes Involving Nitro-Containing Ligands and Crystallographic-Theoretical Description of 3,5-DNB Complexes

“…Moreover, DFT calculations enable the characterization of the electron transfer mechanism in cocrystals involving 3,5-DNBA units and [{Zn(L)(DMF) 4 }·2BF 4 ] α (L = N 2 ,N 6 -di(pyridin-4-yl)naphthalene-2,6-dicarboxamide), in addition to the resulting HOMO-LUMO and bandgap values [ 98 ]. The results show that the LUMO position can be tuned to accept the incoming electron from π-electron-rich ligands.…”