Near-infrared emission ligands

Chen, F.-F., Bian, Z.-Q., Lou, B., et al. (2008) Sensitised near-infrared emission from lanthanides using an iridium complex as a ligand in heteronuclear Ir2Ln arrays. Dalton Transactions, 5577. 

Fig. 30 Structures of Ir2Ln (Ln = Nd, Yb, Er) arrays and corresponding near-infrared emissions. C N denotes cyclometalated ligand ppy, and Y denotes bidentate nitrate anion...

A few paddlewheel diplatinum(III) compounds were reported in the last decade, and some representative examples are presented in Figure 10.24 [145]. It was revealed that the Pt(III)-Pt(III) bond lengths of compounds 210-Cl/Br/I (Entries 12-14, Table 10.14) were influenced by the axial ligands as well as intermolecular lattice packing effects, and these compounds exhibited unprecedented near-infrared emission at room temperature [145cj. 

Seltzer, M.D., Fallis, S., Hollins, R.A., et al. (2005) Curcuminoid ligands for sensitization of near-infrared lanthanide emission. Journal of Fluorescence, 15, 597. 

Lanthanide compounds have attracted attention due to their potential applications as various materials. Their intra-4f electronic transition, the so-called f-f transition, is one of the most discriminative properties and used extensively for many optics, such as lasers, fibers, optical displays, and biosensors [1-3]. The probability of photo absorption is represented by oscillator strength, a dimensionless quantity. The oscillator strengths of f-f transitions are small, typically in the order of 10 , reflecting Laporte forbidden transitions, and their absorption and emission spectra have sharp peaks in visible, near infrared, and near ultraviolet regions. Despite the usefulness of these systems, there are only a few relevant ab initio studies of the f-f transition intensities that explicitly included ligand electrons [4—7] because these calculations are difficult due to the importance of both relativistic and electron correlation effects. 

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