Synthesis, characterization and oxygen sensitivity of cyclophosphazene equipped-iridium (III) complexes

Merve Zeyrek Ongun; Murat Sahin; Tugce Akbal; Neslihan Avsar; Hayriye Karakas; Kadriye Ertekin; Devrim Atilla; Hanife İbişoğlu; Sevinc Zehra Topal

doi:10.1016/j.saa.2020.118490

Synthesis, characterization and oxygen sensitivity of cyclophosphazene equipped-iridium (III) complexes

Spectrochim Acta A Mol Biomol Spectrosc. 2020 Oct 5:239:118490. doi: 10.1016/j.saa.2020.118490. Epub 2020 May 16.

Authors

Merve Zeyrek Ongun¹, Murat Sahin², Tugce Akbal², Neslihan Avsar², Hayriye Karakas², Kadriye Ertekin³, Devrim Atilla², Hanife İbişoğlu⁴, Sevinc Zehra Topal⁵

Affiliations

¹ Dokuz Eylul University, Chemistry Technology Program, Izmir Vocational High School, 35360 Izmir, Turkey.
² Gebze Technical University, Faculty of Science, Department of Chemistry, 41400 Gebze, Kocaeli, Turkey.
³ Dokuz Eylul University, Faculty of Sciences, Department of Chemistry, 35160 Buca, Izmir, Turkey.
⁴ Gebze Technical University, Faculty of Science, Department of Chemistry, 41400 Gebze, Kocaeli, Turkey. Electronic address: ibisoglu@gtu.edu.tr.
⁵ Gebze Technical University, Faculty of Science, Department of Chemistry, 41400 Gebze, Kocaeli, Turkey. Electronic address: sztopal@gtu.edu.tr.

PMID: 32502815
DOI: 10.1016/j.saa.2020.118490

Abstract

In this work, synthesis, characterization and oxygen sensing abilities of the cyclophosphazene-free and phenyl and naphtoxy-substituted cyclophosphazene bearing iridium (III) complexes (Ir-I, Ir-II and Ir-III) were presented. The complexes were characterized by NMR, absorption and emission spectroscopies, luminescence lifetime and quantum yield measurements. The molecules were successfully embedded in the ethyl cellulose matrix to fabricate the oxygen sensing electrospun mats via electrospinning technique. Oxygen induced luminescence of the iridium complexes around 600 nm has been followed as the analytical signal during oxygen sensitivity studies. They exhibited blue shifted, quenched emission towards triplet oxygen. The napthoxy substituted derivative exhibited 2.70 fold enhanced I₀/I₁₀₀ ratio compared to the free form in terms of the relative signal change. Room-temperature luminescence abilities, high photostabilities, large Stoke's shift values extending to 200 nm and high spectral response, especially between 0 and 10% pO₂ make them promising candidates as oxygen probes. The test materials can be stored at the ambient air of the laboratory for at least 24 months.

Keywords: Cyclophosphazenes; Electrospun mats; Iridium (III) complexes; Oxygen sensitivity; Phosphorescence.