Near-Infrared NIR Luminescence from Lanthanide III Complexes

Near-Infrared (NIR) Luminescence from Lanthanide(III) Complexes 

State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P.R. China. Email czn Jjirsm.ac.cn 

More than half of the trivalent lanthanide, Ln(III), ions display NIR luminescence with transition wavelengths longer than 700 nm. The most investigated NIR-emitting lanthanide(III) ions include Nd(III), Yb(III), and Er(III) ions, whereas NIR-emitting Pr(III), Sm(III), Dy(III), Ho(III), and Tm(III) ions have been much less explored. Several of the lanthanide(III) ions are characterized by both visible and NIR emission, including Pr(III), Sm(III), Dy(III), Ho(III), and Er(III). The NIR emission from most of the Ln(III) ions is fluorescent except for that from Pr(III) or Sm(III) ion. Typical NIR emission spectra of Nd(III), Pr(III), Ho(III), Er(III), Tm(III), Yb(III), Dy(III), and Sm(III) are depicted in Eigure 12.1. 

Rare Earth Coordination Chemistry Fundamentals and Applications Edited by Chunhui Huang 

The Yb(III) ion has a single emission line at 0.96-1.03 xm due to the only Fs/2 Fj/2 transition. In view of the relatively long-lived NIR emission together with the highest quantum efficiency for the Yb(III) ion in comparison with that for other NIR emitting Ln(III) ions, the emission from the Yb(III) ion has the most extensive applications in biomedical imaging. The Er(lll) ion affords both visible and NIR luminescence, where the NIR emitting bands 

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