Iridium acetylacetonate explained

Iridium acetylacetonate is the iridium coordination complex with the formula Ir(O₂C₅H₇)₃, which is sometimes known as Ir(acac)₃. The molecule has D₃-symmetry.^[1] It is a yellow-orange solid that is soluble in organic solvents.

Preparation and isomerism

It is prepared from IrCl₃(H₂O)₃ and acetylacetone.^[2] The complex has been resolved into individual enantiomers by separation of its adduct with dibenzoyltartaric acid.^[3]

A second linkage isomers is also known. In the second isomer one of the acetylacetonate ligands is bonded to Ir through carbon.^[4]

Uses

The O₆-bonded isomer has been investigated for use chemical vapor deposition (CVD). One example is the deposition of red phosphorescent emitter compounds used in OLEDs.^{[5] [6]}

The C-bonded isomer has been investigated as a catalyst for C-H activation reactions.^[4]

Notes and References

1. V. G. Isakova, I. A. Baidina, N. B. Morozova, I. K. Igumenov "γ-Halogenated iridium(III) Acetylacetonates" Polyhedron 2000, Volume 19, Pages 1097–1103.
2. James E. Collins, Michael P. Castellani, Arnold L. Rheingold, Edward J. Miller, William E. Geiger, Anne L. Rieger, Philip H. Rieger "Synthesis, Characterization, and Molecular Structure of Bis(tetraphenylcyclopentdienyl)rhodium(II)" Organometallics 1995, pp 1232–1238.
3. Drake, A. F. . Gould, J. M. . Mason, S. F. . Rosini, C. . Woodley, F. J. . The optical resolution of tris(pentane-2,4-dionato)metal(III) complexes. Polyhedron. 1983. 2. 6. 537–538. 10.1016/S0277-5387(00)87108-9.
4. Book: S. M. Bischoff . R. A. Periana . Oxygen and Carbon Bound Acetylacetonato Iridium(III) Complexes. Inorganic Syntheses. 2010. 35. 173. 10.1002/9780470651568. 978-0-470-65156-8.
5. http://pubs.rsc.org/en/content/articlelanding/2004/jm/b313843g "Synthesis of a high-efficiency red phosphorescent emitter for organic light-emitting diodes"
6. http://pubs.acs.org/doi/abs/10.1021/ja003693s "Highly Phosphorescent Bis-Cyclometalated Iridium Complexes:  Synthesis, Photophysical Characterization, and Use in Organic Light Emitting Diodes"