New up-conversion luminescence in molecular cyano-substituted naphthylsalophen lanthanide(iii) complexes

Abstract

ErIII-Centered upconversion emission in LnIII complexes with a cyano-naphthylsalophen ligand.

Radical-Doped Crystalline Lanthanide-Based Photochromic Complexes: Self-Assembly Driven by Multiple Interactions and Photoswitchable Luminescence

“…Intriguingly, the generation of intense NIR fluorescence emission located at 875, 1054, and 1370 nm was observed in the Nd­(III) complex (Figure a), which were assigned to the radiative energy transitions of 4 F 3/2 → 4 I 9/2 , 4 F 3/2 → 4 I 11/2 , and 4 F 3/2 → 4 I 13/2 , respectively, in Nd­(III) ions . It is noteworthy that the NIR emissive intensity continues to decline upon being subjected to irradiation with additional blue light (λ = 460–465 nm), suggesting the photosensitiveness of the NIR emission for the crystalline Nd­(III) complex.…”

“…20 Photoswitchable NIR Fluorescence. Intriguingly, the generation of intense NIR fluorescence emission located at 875, 1054, and 1370 nm was observed in the Nd(III) complex (Figure 4a), which were assigned to the radiative energy 21 It is noteworthy that the NIR emissive intensity continues to decline upon being subjected to irradiation with additional blue light (λ = 460−465 nm), suggesting the photosensitiveness of the NIR emission for the crystalline Nd(III) complex. After exposure to ozone, the NIR emissive intensity almost recovers to the original state (Figure S36), demonstrating the reversibility of the photoswitchable NIR luminescence for the Nd(III) complex.…”

Metal-Based Linear Light Upconversion Implemented in Molecular Complexes: Challenges and Perspectives

“…39−41 Attempts to prepare discrete molecular entities displaying upconversion using ETU or CR mechanisms can be traced back to the suggested formation of (i) ionic [IR-806][Er(tta) 4 ] pairs in nonpolar organic solvents (Figure 9a) 42 and (ii) fluoro-bridged {[Er(I-DOTA)] 2 F} + dimers in water (Figure 9b). 35 This strategy has been extended in materials science where polynuclear lanthanide complexes are statistically doped with ytterbium (S) and erbium (A), while yttrium is used as a "diluting" cation either in the solid state 43 or in solution. 44 Interestingly, the discrete [CrErCr(dipy-pybzimpy) 3 ] 9+ complex, which corresponds to the first report in 2011 of a planned molecular-based upconversion induced under reasonable excitation intensities, exploits the ETU mechanism (Figure 10a).…”

Upconversion in a d–f [RuYb3] Supramolecular Assembly

“…Since the pioneering work of Piguet and co-workers in 2011, only few examples have been reported, − but this burgeoning field sees each new iteration as a step forward toward better molecular UC devices. Except for the rare case of molecular UC based on triplet–triplet annihilation (TTA) with organic dyes, all examples rely on successive ascendances of the energy ladder using long-lived d–d or f–f electronic transitions, sometimes using indirect excitation by an organic near-infrared (NIR) absorbing dye. , This is typically the case for the Cr to Er energy transfer in hetero-trinuclear [Cr 2 ErL 3 ] helicates, for solution-state Yb to Tb , and Yb to Er − UC within hetero-polynuclear assemblies, or for Yb to Cr in solid mixtures . Interestingly, Howard and Turshatov reported an atypical case of UC using Yb sensitizers generating TTA by energy transfer from the Yb excited state to the triplet level of a rubrene annihilator .…”