Efficient 1400–1600 nm Circularly Polarized Luminescence from a Tuned Chiral Erbium Complex

Abstract

Novel chiral Er complexes based on both enantiomers of extended i PrPyBox (2,]pyridine) show strong near-infrared circularly polarized luminescence (CPL) within the 1400 to 1600 nm spectral region under 450 nm irradiation. CPL activity in this region, despite being particularly rare, would open the way to potential applications in the domain, e.g., of fiber-optic telecommunications and free-space long-distance optical communications employing circularly polarized light. Moreover, the long wavelength excitation is advantageous for applications in the field of (circularly polarized) microscopy and bioimaging.

Impact of the experimental bandwidth on circularly polarized luminescence measurements of lanthanide complexes: the case of erbium(iii)

“…Very recently, the NIR-CPL detection was extended to the wavelength range of Er(III) complexes around 1550 nm. 8,[15][16][17][18] It is important to note that measuring NIR-luminescence and especially NIR-CPL of lanthanide complexes remains a technical challenge even using the latest advancements in CPL spectrometers equipped with highly sensitive InGaAs detectors (PEM or CCD camera). This is mainly owed to the typically low quantum yields of lanthanide NIR-emitters.…”

General Strategy to Prepare Nondoped Circularly Polarized Luminescent Liquid Crystal Materials with Tunable Performance

“…One of the most common methods to obtain CPL materials is to covalently link luminescent and chiral components through chemical synthesis. A series of CPL materials were obtained using this method, including metal complexes, 6,7 organic small molecules, 8−11 π-conjugated polymers, 12−14 and so forth. In addition, CPL materials can also be obtained by introducing chiral dopants or chiral environment into achiral luminescent materials through physical doping method.…”

High Quantum Yields from Perfluorinated Binolate Erbium Complexes and Their Circularly Polarized Luminescence

“…The groups of Zinna and Di Bari have recently synthesized strong erbium CPL emitters utilizing a Shibasaki-type complex of Binol with the tetramethylguanidinium counterion (Binol) 3 Er(TMG-H) 3 , 5a as well as pyridine-bisoxazoline complexes Er( i PrPyBox-NMe 2 ) 2 •3OTf 5b and tetrakis-heptafluorobutyrylcamphorate (hfbc) complexes CsEr(hfbc) 4 , 5a with g lum up to 0.83, quantum yields ≤0.03%, and decent CPL brightness values (B CPL ≤ 0.70 M −1 cm −1 ). 5,6 Generally speaking and irrespective of circular polarization, erbium complexes emitting in the 1550 nm region typically have low quantum yields (0.01−5%). 4−8 The luminescence of Er(III) complexes is susceptible to nonradiative vibrational quenching due to the matched energy levels of the overtones of C sp2 -H vibrations of the ligands and the emissive state of erbium; hence, low quantum yields are typically obtained with organic ligand-based sensitization.…”