Ligand-based emission

A ligand-based emission is also proposed in the complex [PhC = CAu]n, which displays a honeycomb network with PhC = C pillars [16]. In this case, the Au-Au interactions are even shorter than in the previous cases (2.98(1)-3.26(1) A) and the emission spectrum displays a very complicated pattern with peak maxima at 413,468,... 

Figure 33 Structures of the (C N)R(O O) complexes used in the discussion of ligand-based emission color tuning.

Michalec JF, Bejune SA, McMillin DR (2000) Multiple ligand-based emissions from a platinum(II) terpyridine complex attached to pyrene. Inorg Chem 39 2708-2709... 

LMCT or MLCT and a significantly strong emission with the maximum peak at 392 nm originated from ligands-based emission [114]. 

Recently Zhao and coworkers investigated a series of new Ir complexes based on quinoline derivatives and different S-diketonate ligands. It has been observed that the PL efficiency is improved on replacing acac with pmip. This behavior has also been observed for the electrophosphorescence properties. The explanation is that the T state of pmip ca 23000 cm ) is higher than the one for acac ca 22200 cm ). Consequently, for Ir complexes containing the pmip ligand the emission is dominated by MLCT d r(Ir)- 7r (CAN), where (CaN) represents the quinoline derivatives. 

The synthesis, optical, and structural properties of another Pt(II) polyyne-containing biphenyl moiety, P12, were reported recently.44 The system has also been extended to the Au(I) and Hg(II) congeners (see Sections IV and V). The influence of the metal center on the spatial extent of S and T excited states was characterized in detail. The ligand-based phosphorescence emissions can be harvested by the heavy-atom effect of these transition metals, which facilitates efficient intersystem crossing from the S] state to the T] state. 

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