Synthesis of poly(3,4-azopyridylene) and oxygen-binding affinity of its complex with cobaltporphyrin

Bao Qing Shentu, Zhi Xue Weng, Hiroyuki Nishide

Research output: Contribution to journalArticle

Abstract

Synthesis and characteristics of poly(3,4-azopyridylene) (PAP), conductivity and oxygen-binding affinity of its complex with meso-α,α,α,α-tetrakis(o-pivalamidophenyl) porphyrinatocobalt(II) (CoP) were studied. PAP was prepared by oxidative polymerization of 3,4-diaminopyridine (DAP) in DMF solution using CuCl/pyridine as the catalyst. IR and NMR results showed that the peak of amido group in DAP was converted to the azo group in PAP and a π conjugated polymer was synthesized. The average molecular weight of PAP was determined to be 5.0 × 103. The PAP-CoP complex was prepared by complexing the pyridyl group of PAP with the fifth coordination site of CoP in DMF solution. In comparison with the CoP complex with a non-π conjugated polymer, the PAP-CoP complex shows good electroconductivity of 5.8 × 10-6 S cm-1. The PAP-CoP complex displays a reversible change in the UV-Visible absorption spectrum from the deoxy form to the oxy or oxygen-binding one with an isosbestic point, in response to the partial oxygen pressure of the atmosphere. The oxygen-response behavior was monitored at the absorbance ascribed to the oxy form at 548 nm to give the oxygen-binding affinity. The oxygen-binding equilibrium curves of PAP-CoP complex obey a Langmuir isotherm. DMF has great effects on the oxygen-binding properties of the PAP-CoP complex. The oxygen-binding affinity of PAP-CoP complex in the solid state is higher than that in DMF solution. With decreasing temperature, the oxygen-binding affinity of the PAP-CoP complex increases.

Original languageEnglish
Pages (from-to)417-422
Number of pages6
JournalChinese Journal of Polymer Science (English Edition)
Volume23
Issue number4
DOIs
Publication statusPublished - 2005 Jul

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Keywords

  • Cobaltporphyrin
  • Conductivity
  • Oxygen-binding
  • Poly(3,4-azopyridylene)

ASJC Scopus subject areas

  • Polymers and Plastics
  • Materials Chemistry

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