Synthesis, characterization and thermal poroperties of oligo-N,N′-bis (2,4-dihydroxybenzylidene) ethylenediamine and its cobalt (II) and manganese (II) complexes

DEMETGÜL C., Karakaplan M., Serin S.

Designed Monomers and Polymers, vol.11, no.6, pp.565-579, 2008 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 11 Issue: 6
  • Publication Date: 2008
  • Doi Number: 10.1163/156855508x363852
  • Journal Name: Designed Monomers and Polymers
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.565-579
  • Keywords: Oligo-N,N′-bis (2,4-dihydroxybenzylidene) ethylenediamine, Oligomer-metal complexes, Oxidative polycondensation, Schiff base oligomer, Thermal properties
  • Hatay Mustafa Kemal University Affiliated: No

Abstract

In this study, the new oligomer Schiff base oligo-N,N′-bis (2,4-dihydroxybenzylidene) ethylenediamine (O-DHBEDA), with a double azomethine group, was synthesized by oxidative polycondensation (OP) of N,N′-bis (2,4-dihydroxybenzylidene) ethylenediamine (DHBEDA) with NaOCl as an oxidant in an aqueous alkaline medium at 90°C. About 69.3% DHBEDA was converted to O-DHBEDA. The structures of the products were studied by UV-Vis, FT-IR, 1H-NMR, 13C-NMR and elemental analysis. According to gel-permeation chromatography (GPC) analysis of O-DHBEDA, the number-average molecular weight (M n), weight-average molecular weight (M w) and PDI values were found to be 5255 g/mol, 9116 g/mol and 1.73, respectively. During the polycondensation reaction, a part of the azomethine (-CH=N-) groups oxidized to aldehyde (CHO) groups (approx. 4%). Oligomer-metal complexes of oligo-N,N′-bis (2,4-dihydroxybenzylidene) ethylenediamine (O-DHBEDA) with Co (II) and Mn (II) were synthesized and characterized by FT-IR, UV-Vis, TG-DTA and atomic absorption spectroscopy (AAS). TG/DTA analyses were shown to be stable of O-DHBEDA against thermo-oxidative decomposition. The residue values of DHBEDA, O-DHBEDA, O-DHBEDA-Co and O-DHBEDA-Mn were found to be 0%, 7.1%, 14% and 13.4%, respectively, at 1000°C. © 2008 Koninklijke Brill NV.