Structure-property relationships are essential for the design of compounds with particular properties. Elisabeth Holder, University of Wuppertal, Germany, and co-workers at the University of Regensburg and University of Regensburg, Germany, have designed and characterized a series of neutral heteroleptic iridium(III) complexes. General design rules for Ir(III) emitters are elucidated by a gradual enhancement of the asymmetric nature of the heteroleptic species.

The described synthesis is less demanding and cheaper than other approaches and was able to be optimized to give surprisingly high yields. The general rules might be able to be transferred to other applications like OLED’s or imaging, as deactivation of light-emission induced by oxygen or temperature are also of general interest in these fields.

• Structure–Property Relationship of Red- and Green-Emitting Iridium(III) Complexes with Respect to Their Temperature and Oxygen Sensitivity
  N. Tian, D. Lenkeit, S. Pelz, L. H. Fischer, D. Escudero et al.,
  Eur. J. Inorg. Chem. 2010.
  DOI: 10.1002/ejic.201000610