Lanthanide Tetrafluoroterephthalates for Luminescent Ink‐Jet Printing

Abstract

Lanthanide tetrafluoroterephthalates, Ln 2 ftp 3 ·6H 2 O (Ln = Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Tm, Yb), (Eu x Tb 1-x ) 2 ftp 3 ·6H 2 O, and (Eu x Tb 1-x ) 2 ftp 3 (Phen) 2 ·2H 2 O (Phen = o-phenanthroline) were obtained for the first time and studied in detail. Water IntroductionOne of the prospective applications of luminescent materials is security printing, in which ink-jet printing plays an important role. A variety of luminescent materials have been considered for this application; however, most of them suffered from certain problems that hampered their practical use; for example, quantum-dot-based inks [1] are toxic, organic dyes [2] have small Stokes shifts, and inorganic lanthanide-based inks [3] have low brightness.Lanthanide coordination compounds (Ln CCs) possess features that predetermine their high potential as security printing dyes, namely, high brightness of luminescence, high thermal and UV stability, low toxicity, and a large Stokes shift. [4,5] As there is a large energy difference between the absorbing state of the ligand and the emitting state of the lanthanide, these materials typically absorb UV radiation and emit in the Vis/IR range. [6,7] Thus, they are colorless if observed with the naked eye but exhibit intense luminescence if irradiated with UV light, which is very important for this application.Water is one of the most suitable solvents for ink-jet printing, because it is an environmentally friendly solvent, possesses suitable viscosity, and does not induce the corrosion of printer parts; thus, water-soluble luminescent inks are highly sought.[a]

Energy transfer between Eu3+ and Nd3+ in near-infrared emitting β-triketonate coordination polymers

“…The resulting solids are isolated with variable degrees of solvation, which has been found previously for these Ln 3+ /Ae + based complexes. 19,20 The Eu 3+ /Nd 3+ mixed assemblies were synthesised in a similar fashion to the {[Ln(Rb)(mtbm) 4 ] 2 } n , except for the use of mixtures of hydrated EuCl 3 and NdCl 3 in molar ratios of Nd 3+ of 0.25 (3), 0.50 (4) and 0.75 (5).…”

“…In eqn (4) and (5), τ q and τ u are the 5 D 0 decay lifetime of Eu 3+ in the presence or absence of the quencher (Nd 3+ ), respectively.…”

“…The NIR region is of particular interest due to potential applications in a wide range of fields including night vision devices, telecommunication signalling and life science. [1][2][3][4][5][6] Despite the listed advantages, trivalent lanthanoid cations cannot be directly excited with high efficiency, as intraconfigurational f-f transitions are parity and often spin forbidden. Therefore, π-conjugated ligands are routinely used as sensitisers, because of their greater efficiency in absorbing incident light with con-sequent energy transfer to lanthanoid excited states.…”

On the Structural Features of Substituted Lanthanide Benzoates

“…Pentafluorobenzoic acid (Hcarb 14 ) demonstrates p K a of 1.6–1.8 . This results in the extreme lability of the complexes with fluorobenzoate‐anions: their composition depends not only on the lanthanide ion and the synthesis conditions, but also on the crystallization conditions , , , , , …”

“…Among those, lanthanide benzoates play an important role due to their high stability, excellent luminescence properties and ease of chemical modification . Nowadays undirected synthesis and search for new material precursors is more and more substituted by the directed chemical design, allowing to obtain the probes with the specific properties demanded by the particular application . At the same time, lanthanide benzoates are known for their high lability, resulted from high acidity of benzoic acids.…”