Synthesis of biscyclometalated iridium(III) acetylacetonate complexes via a 15 min bridge-splitting reaction, their characterisations and photophysical properties


Altinolcek N., Aydemir M., TAVASLI M., Dos Santos P. L. , Monkman A. P.

JOURNAL OF ORGANOMETALLIC CHEMISTRY, vol.851, pp.184-188, 2017 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 851
  • Publication Date: 2017
  • Doi Number: 10.1016/j.jorganchem.2017.09.028
  • Journal Name: JOURNAL OF ORGANOMETALLIC CHEMISTRY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.184-188
  • Keywords: Bridge-splitting, Biscyclometalated iridium(III) complexes, 2-Phenylpyridine, Formyl group, LIGHT-EMITTING-DIODES, PHOSPHORESCENT IR(III) COMPLEXES, ELECTROCHEMICAL PROPERTIES, 2-PHENYLPYRIDINE LIGANDS, STATE PROPERTIES, EMISSION COLOR, RED, BLUE, DEVICES, ELECTROLUMINESCENCE
  • Bursa Uludag University Affiliated: Yes

Abstract

Chloro-bridged diiridium(III) complexes (4a and 4b) were subjected to a bridge-splitting reaction with acetylacetone and sodium carbonate in 2-ethoxyethanol. The reaction was complete within 15 min and two novel biscyclometalated iridium(III) acetylacetonate complexes (5a and 5b) were successfully obtained in 41% and 63%, respectively. Complexes (5a and 5b) were fully characterised by H-1, C-13 NMR, FT-IR and elemental analysis. UV-Vis spectra of complexes (5a and 5b) showed two absorption bands: a strong one appears below 400 nm due to ligand-centered (LC, pi-pi*) transitions and the weak one arises between 400 and 600 nm due to metal-to-ligand charge-transfer (MLCT, d-pi*) transitions. The emission of the complexes (5a and 5b) arises in the red region of the spectrum, emitting ca. 675 nm for 5a and ca. 625 nm for 5b. A short emission lifetime (62 ns) for complex 5a indicates emission originates from (LC)-L-3 transitions. However longer emission lifetime (657 ns) for complex 5b confirms that the emission totally results from (MLCT)-M-3 transitions. (C) 2017 Elsevier B.V. All rights reserved.