Highly luminescent lanthanide complexes sensitised by tertiary amide-linked carbostyril antennae

Abstract

Carbostyrils are among the most widely used sensitising antennae for luminescent lanthanides; they afford bright complexes with Eu and Tb, and can also sensitise the emissions of the less commonly used Sm, Dy, Yb and Nd. Systematic studies on the effect of structural variations on the photophysical properties and lanthanide sensitising abilities of carbostyrils can therefore have a large impact. We replaced the secondary amide linker that connects the metal binding site to the antenna with a carboxymethylsubstituted tertiary amide. Eight Tb and Eu complexes were prepared. All had higher lanthanide luminescence quantum yields (Φ Ln ) than their secondary amide analogues; three Tb emitters had Φ Tb > 40%. Eu complexes had Φ Eu up to 11.6%. The antenna singlet and triplet excited states are slightly shifted, while the metal coordination sphere is unchanged by the introduction of the carboxymethyl group.

A novel DOTA-like building block with a picolinate arm for the synthesis of lanthanide complex-peptide conjugates with improved luminescence properties

“…derivatives [69,84,89] and octadentate DOTA derivatives [89,90]. This confirms that the DO3Apic chelate is a valuable alternative to DOTA to improve the luminescence properties of Ln 3+ complexes-peptide conjugates.…”

“…5 % for their Zn-bound forms. However, these low values of sens ACD (< 10 %) are due to the remoteness of the antenna in comparison with coordinated antennas that offers higher sensitization efficiencies (20-100 %) [69,84,[89][90][91]. The remoteness of the antenna and the subsequent low sensitization efficiency is clearly restricting the performance of these probes.…”

Smart lanthanide antennas for sensing water

“…9,10 This effect can be exploited to develop water sensors, paving the way for a new application of lanthanide probes, since reports on the use of this strategy to design water sensors have been very scarce. 2,[11][12][13][14] Even though b-dicarbonyl compounds are among some of the most studied ligands for lanthanides and quinolin-2-ones are among the most widely used sensitizing antennas, [15][16][17][18][19][20] up to date, no quinolin-2(1H)-one-derived antennas capable of assembling directly with lanthanide ions in solution have been described. In general, antennas that directly assemble lanthanide cations are bulky multidentate ligands able to coordinate the cations with a high coordination number.…”

A High-Throughput Method To Measure Relative Quantum Yield of Lanthanide Complexes for Bioimaging

“…7–19 Small chemical modifications to the antenna and chelate structure can result in large changes in the corresponding lanthanide complex quantum yield. 9,12,20 A significant impediment to selection and development of suitable bifunctional lanthanide complex systems is the rapid determination of effective, lanthanide-based quantum yields (Φ Ln ). 21–23 Lower-quality monochromators or lack of long pass filters can result in codetection of an artifact arising from the second order of the excitation light, which can coincide with lanthanide-based emission peaks.…”