Photoluminescence of Visible and NIR‐Emitting Lanthanide‐Doped Bismuth‐Organic Materials

Abstract

A bismuth-organic compound containing 2,2':6'2"-terpyridine (terpy) and 2-thiophenecarboxylate (TC), of the general formula (terpy)Bi(κ -TC) ⋅0.47 H O (BiOM-1), has been synthesized under hydrothermal conditions. Addition of a lanthanide nitrate solution to the reaction mixture led to statistical replacement of the bismuth centers, and yielded isomorphous lanthanide containing compounds Bi Ln OM-1 (Ln=Nd, Sm, Eu, Tb, Dy, Er, and Yb) that showed bismuth and/or ligand sensitized lanthanide-centered emission, and the first example of NIR emission from a lanthanide doped BiOM. The structure was determined by single-crystal X-ray diffraction, and the level and uniformity of lanthanide ion incorporation into the bismuth host was determined by ICP-OES and electron microprobe analysis. For the visible emitters, lifetime data and quantum yields are presented. A high efficiency of sensitization was calculated for the europium analog (50.1 %), showing significant improvement over previously reported europium thiophenecarboxylates. These novel materials may provide strategies to address concerns over the long-term sustainability of the rare earth elements, especially relating to optical devices.

Synthesis and photoluminescence of three bismuth(iii)-organic compounds bearing heterocyclic N-donor ligands

“…[65][66][67][68] We have also previously reported a mixed ligand Bi-terpy-thiophenemonocarboxylate compound. 37 The structural unit of 3 is isostructural to the bromobismuth-phen dimer published by White et al, [Bi 2 Br 6 ( phen) 4 ], though attempts by the authors to produce the chloride analog were reportedly unsuccessful. 42 Interestingly, the chlorobismuth dimer is accessible using terpy as a capping ligand, possibly owing to the increased denticity and ability of terpy to better saturate the metal coordination sphere.…”

“…Beyond their precedence in luminescent materials research, [32][33][34][35] these ligands have been shown to restrict dimensionality through capping coordination modes to yield molecular units. [36][37][38][39][40] Moreover, the aromaticity of the ligands may promote supramolecular interactions such as π-π stacking, which have been shown to impact the materials properties of hybrid inorganic-organic complexes. 41 The obtained compounds,…”

Similarities of Coordination Polymer and Dimeric Complex of Europium(III) with Joint and Separate Terpyridine and Benzoate

“…[ 1–4 ] Since then, a number of publications presented coordination compounds of Eu 3+ with terpyridine itself or its derivatives. [ 5–18 ] In these compounds, trivalent europium as 4f‐4f emitter is influenced by the chemical environment rather in the intensity of 4f‐4f transitions than in nature of the transitions. [ 19–21 ] In addition, terpyridine and its derivatives are good sensitizers of trivalent Eu 3+ photoluminescence properties.…”

Two Series of Lanthanide Coordination Polymers and Complexes with 4′‐Phenylterpyridine and their Luminescence Properties

“…They emit throughout the visible and NIR, and some of the typical NIR emitters also have possible transitions in the visible range,, but these are usually too weak to be readily observed. Terpyridine and its derivatives are known to enhance trivalent lanthanide luminescence, but mostly photophysical properties of these compounds are well studied for the standard visible emitters, such as Eu 3+[6–14] and Tb 3+ , whereas other rare earth metal ions such as Er 3+[13–16] or Tm 3+[17] have been investigated to a lesser extent. For the ligand 4′‐phenyl‐2,2′:6′,2′′‐terpyridine (ptpy), complexes especially with transition metals were studied .…”