Cyclometallating ligands

Reaction of the cyclometallated complexes 244-246 with pyrazole and excess sodium hydride affords cyclic dimers 247 (990M3991), where C N denotes the corresponding cyclometallated ligand in accordance with structures 244-246. The [Pt2(thienylpyridine)2(/j.-pz)](C104)3] is known as well. 

Dinuclear cyclometallated complexes are usually prepared starting from the metal chloride and the cyclometallating ligand (Figure 5, top). The same type of synthesis can be used to prepare cyclometallated complexes of high nuclearity. As an example, the recently reported synthesis of a hexanuclear cyclometallated complex is shown in Figure 5, bottom. ... 

Figure 5. (a) Metal chlorides can react with simple cyclometalating ligands to give dinuclear cyclometallated complexes, (b) Schematic representation of the synthesis of a hexanuclear complex containing cyclometallated units. ... 

The following syntheses detail the preparation of complexes containing typical examples of cyclometallated ligands. One of the most extensively studied... 

Cyclometallated gold(III) dihalide complexes also act as useful precursors for the synthesis of gold(III) complexes with thiolate and other sulfur donor ligands. The cyclometallated ligand stabilises the gold(III) centre towards reduction, which is important due to the reducing potential of sulfur-based ligands. 

Finally, several patents have covered the photophysical properties (electroluminescence, phosphorescence) of metal complexes containing C,N cyclometallated ligands.116... 

The complexes with ppy- as cyclometalating ligand show similar changes. The luminescence of the Rh3+ complexes, which was quenched in solution at room temperature, can be recorded in PMMA at 10 K and shows structured... 

Keywords Iridium complexes Cyclometalating ligands Phosphorescence Electrochemistry Multicomponent arrays OLEDs Photoinduced processes... 

From this diagram, one may notice that ca. 90% of the known luminescent Ir(III) complexes, mostly from cyclometalating ligands, have been reported in the last 6 years. One relevant reason for this trend is related to the use of the cyclometalated complexes for OLED fabrication [9-12], with those of Ir(III) exhibiting relevant advantages with respect to complexes from other metals [13]. 

The interesting points for complexes of bidentate cyclometalating ligands are that ... 

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