Study of complexes of poly(vinyl pyrrolidone) with copper and cobalt on solid state

Abstract

A polymer-metal complex is a metal complex containing a polymer ligand, showing a remarkably specific structure in which central metal ions are surrounded by a colossal polymer chain. Based on this polymeric ligand, the polymer-metal complex has interesting and important characteristics, especially catalytic activities. This activity is different from that of the corresponding ordinary metal complex of low molecular weight. In this work we studied the synthesis and characterization, in the solid state, of different poly(vinyl pyrrolidone)-cobalt (PVP/Co) and -copper (PVP/Cu) complexes. We used differential thermal analysis and FTIR as the experimental techniques.

A New Approach for the Fabrication of Cytocompatible PLLA-Magnetite Nanoparticle Composite Scaffolds

“…The introduction of nanoparticles in the polymer matrix caused their molecular weight to be reduced by 56.8%, 57.7%, and 78% for samples of PLLA-10%nFe 3 O 4 , PLLA-30%nFe 3 O 4 and PLLA-50%nFe 3 O 4 respectively. When the nanoparticles are introduced into the scaffolds, their metallic cations interact with the carbonyl groups of PLLA and provoke macromolecular chain scissions, forming a type of metal-polymer complex that in turn shortens the chains before the onset of the in vitro degradation process [48]. This all agrees with the FTIR results, in which there are stretching and flexural displacements of all the bands of C=O, and stress displacements of -C-O-.…”

Poly(l‐lactide) and Its Cu(II) and Cr(III) Complexes

“…Over and above 3500 cm −1 , the spectra of the polymer complexes show an intense band in the area of interfacial tension of the O–H group, which indicates the presence of coordination water. Thermal treatment failed to eliminate the residual water completely, which leads us to suppose that the water forms as part of the chemical structure of the polymer complexes, which is to say that the water molecules are coordinated to the copper and chromium 17…”

“…Figures 5 and 6 show the FTIR spectrum of PLLA and its Cu(II) and Cr(III) complexes. The PLLA spectrum shows a strong band at 1639 cm −1 , which may be attributed to the carbonyl band of the ester groups, and multiple bands within 1000–1200 cm −1 , which were due to symmetric and asymmetric stretching vibrations of the ether group 13,15–17. The CO stretching vibrations shift to a lower frequency—1602 cm −1 for the Cu(II) complexes and 1614 cm −1 for the Cr(III) complexes—due to considerable charge transfers from carbonyl oxygen to the Cu(II) ion and to the Cr(III) ion, respectively.…”

Synthesis and Characterisation of Poly (Vinylpyrrolidone) – Nickel (II) Complexes

“…Such complexes show a specific structure in which central metal ions are surrounded by a gigantic polymer chain. Polymer-metal complexes exhibit many interesting characteristics such as improved thermal stability [1], hardness and especially catalytic activities, which are different from that of the corresponding ordinary metal complexes of low molecular weight [1][2][3].…”

“…Most of the polymer-metal complexes studied so far belong to Werner type. But those of non-Werner type are more attractive to chemists because of their specific catalytic activities [2][3][4]. In recent years the study of polymermetal complexes has been of great interest to chemists as they serve as excellent models for metallo-enzymes [4,5].…”