Neutral luminescent bis(bipyridyl) osmium(II) complexes with improved phosphorescent properties
A new class of neutral bis(isocyanoborato) bis(bipyridyl) Os(II) complexes with the general formula of [Os(N–N)2(CNBR3)2] (N–N = bpy, 4,4′-Me2bpy; R = C6F5, C6H5) were prepared with simple synthetic methodologies. One of these complexes was structurally characterized by X-ray crystallography. Unlike most of the neutral bis(bipyridyl) Os(II) complexes, which are very weakly emissive or nonemissive, these isocyanoborato complexes displayed intense orange to red phosphorescence with a luminescent quantum yield up to 0.09 in CH2Cl2 solution at room temperature. The photophysical and electrochemical properties of these complexes were also investigated. Detailed photophysical study showed that these complexes exhibited significantly enhanced emission properties over other reported neutral bis(bipyridyl) Os(II) complexes. In addition, it also revealed that the photophysics, electrochemistry, and excited state properties can be fine-tuned or modified through the functionalization of isocyanoborate ligands.
Chu, W.,Yiu, S.,& Ko, C. (2014). Neutral luminescent bis(bipyridyl) osmium(II) complexes with improved phosphorescent properties. Organometallics, 33 (23), 6771-6777. http://dx.doi.org/10.1021/om500630c