Synthesis and Stimuli-Responsive Properties of Metallo-Supramolecular Phosphazene Polymers Based on Terpyridine Metal Complexes


Sezer S., KÖYTEPE S., GÜLTEK A., SEÇKİN T.

JOURNAL OF INORGANIC AND ORGANOMETALLIC POLYMERS AND MATERIALS, vol.31, no.8, pp.3389-3405, 2021 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 31 Issue: 8
  • Publication Date: 2021
  • Doi Number: 10.1007/s10904-021-02008-y
  • Journal Name: JOURNAL OF INORGANIC AND ORGANOMETALLIC POLYMERS AND MATERIALS
  • Journal Indexes: Science Citation Index Expanded, Scopus, Academic Search Premier, Chemical Abstracts Core, Chimica, Compendex, INSPEC
  • Page Numbers: pp.3389-3405
  • Keywords: Metallo-supramolecular polymers, Smart polymers, Cyclotriphosphazene based polymers, Terpyridine ligands, DRUG-DELIVERY, CHEMISTRY, HYDROGELS, SMART, GELS

Abstract

In this study, terpyridine functionalized phosphazene based metallo-supramolecular polymers were synthesized by three step reaction method. In the first step, 4 '-(4-aminophenyl)-2,2 ':6 ',2 ''-terpyridine was synthesized with p-nitro benzaldehyde and 2-acetylpyridine. Then, the monomer containing six terpyridine (TPY) units attached to the phosphazene was prepared from 4 '-(4-aminophenyl)-2,2 ':6 ',2 ''-terpyridine and hexachlorocyclotriphosphazene by a condensation reaction. Finally, metallo-supramolecular phosphazene polymers were synthesised with these TPY functional phosphazenes and different transition metal ions (Cu, Co, Ni, and Zn ions). Prepared metallo-supramolecular polymers containing phosphazene unit were investigated by elemental analysis, different spectroscopic methods, energy dispersive X-ray spectrometry (EDX) and thermal analysis techniques. The stimuli-responsive, optoelectronic and spectroscopic properties of the synthesised metallo-supramolecular phosphazene polymers were investigated for external effects with UV-Vis spectroscopy and electro-analytic techniques. In addition, competitive ligand effect on these metallo-supramolecular polymers was examined with ethylenediaminetetraacetic acid (EDTA). The resulting metallo-supramolecular polymers containing phosphazene unit show very fast stimuli-responsive properties, such as 3 s. they also showed a single reversible redox structure resulting from the bonding of homometallic segments to polymer chain. In addition, they showed d-pi transition (in the range of lambda = 330-550 nm) depending on the metal (Co, Ni and Zn) ion forming the supramolecular structure. The addition of competing EDTA ligands caused the degradation of metallo-supramolecular polymer structures. These metallo-supramolecular phosphazene polymers are a good alternative smart material for opto-electronic, electrochromic, photochromic and intelligent material applications.