Synthesis and Optoelectronic Properties of Cationic Iridium(III) Complexes with o-Carborane-Based 2-Phenyl Benzothiazole Ligands

A series of cationic cyclometalated iridium(III) complexes with o-carborane cage on the main ligand of 2-phenylbenzothiazole were synthesized. The prepared iridium complexes (C1-C6) were fully characterized by UV-vis, NMR, and FT-IR spectra. The exact molecular structure of complex C1 was further studied by single crystal X-ray diffraction analysis. The different substitution position of o-carborane on the 2-phenylbenzothiazole ring lead to obvious differences in the emission properties of the synthesized complexes. The o-carboranyl unit results in a bathochromic shift of 10 nm in the fluorescence emission spectrum of C2. In addition, the presence of an o-carborane fragment promoted the strong fluorescence intensity of C1 and C4, which can be used as a tool to effectively boost the intensity of fluorescence properties. The emission fluorescent behavior of iridium(III) complexes can be facilely tuned by structural variations in the main ligands of these materials.

Automated summary

A series of cationic cyclometalated iridium(III) complexes with o-carborane cage on the main ligand of 2-phenylbenzothiazole were synthesized and characterized. The different substitution positions of o-carborane on the 2-phenylbenzothiazole ring led to significant differences in the emission properties of the synthesized complexes. The presence of an o-carborane fragment promoted strong fluorescence intensity in certain complexes, serving as a tool to effectively enhance fluorescence properties.