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In this work, the synthesis and single crystal structures of Am( III ) and Cm( III ) thiocyanate complexes are reported along with an isostructural series of lanthanide thiocyanate complexes. Because the complexes are isostructural, a comparative study of the metal–thiocyanate bonds was conducted using Raman spectroscopy indicating very similar and electrostatic metal–ligand interactions.
This minireview summarizes and discusses recent progress on the use of nanoparticles in lanthanide and actinide chemistry. We examine different types of nanoparticles and critically analyze their performance in a comparative mode.
In this article, a series of luminescent lanthanide β-diketonate solid solutions, with the formula of TBAEu x M 1– x (TTA) 4 (TBA = tetrabutylammonium; M = La or Gd; TTA = 2-thenoyltrifluoroacetonate), are synthesized by co-precipitation. In the solid solutions, the emission efficiency of Eu 3+ is significantly increased with the presence of non-luminescent chelates TBALa(TTA) 4 and TBAGd(TTA) 4 . Low temperature luminescence spectroscopy studies indicate that the TTA – ligands in these non-luminescent chelates do emit phosphorescence with long lifetime. However, the ligand phosphorescence is strongly quenched in solid solutions with the luminescent chelate TBAEu(TTA) 4 , providing strong evidence for intermolecular energy transfer through the triplet excited states of the ligands. Here, a quantitative analysis of Eu 3+ emission enhancement and TTA – phosphorescence quenching reveals that each Eu 3+ center may receive excitation energy from about 30 TTA – ligands, suggesting that the excitation energy has become exciton-like in the solid solutions. Based on the crystallography analysis of TBALn(TTA) 4 , it is discovered that TTA – ligands in neighboring Ln(TTA) 4 – units may form π–π stacks with intermolecular distance ≤3.5 Å, thus enabling efficient triplet exciton diffusion via exchange interaction.
This review surveys cellular and biomolecular methods to harvest f-block elements, emphasizing how recent characterization of lanthanide-utilizing bacteria is being translated into technologies to extract, separate, and sense these valuable elements.
3,4,3-LI(1,2-HOPO) can be used as a HPLC chelating agent, promoting lanthanide and trivalent actinide separation without column modifications.
Here, the Boron–Chalcogen Mixture method was used to obtain single crystals of the previously extremely difficult to synthesize lanthanide orthothioborates to investigate their structures and their structurally connected optical behavior, such as second harmonic generation. Using a combined halide and polychalcogenide flux, the BCM method yielded single crystals of LnBS 3 (Ln = La, Ce, Pr, Nd), which are isostructural and crystallize in the non-centrosymmetric space group, Pna2 1 . Second harmonic generation measurements confirmed the expectation that LaBS 3 would exhibit a strong SHG response, measured at 1.5 × KDP.
Ligand selectivity to specific lanthanide (Ln) ions is key to the separation of rare earth elements from each other. Ligand selectivity can be quantified with relative stability constants (measured experimentally) or relative binding energies (calculated computationally). The relative stability constants of EDTA (ethylenediaminetetraacetic acid) with La 3+ , Eu 3+ , Gd 3+ , and Lu 3+ were predicted from relative binding energies, which were quantified using electronic structure calculations with relativistic effects and based on the molecular structures of Ln–EDTA complexes in solution from density functional theory molecular dynamics simulations. The protonation state of an EDTA amine group was varied to study pH ~7 and ~11 conditions. Further, simulations at 25 °C and 90 °C were performed to elucidate how structures of Ln–EDTA complexes varying with temperature are related to complex stabilities at different pH conditions. Relative stability trends are predicted from computation for varying Ln 3+ ions (La, Eu, Gd, Lu) with a single ligand (EDTA at pH ~11), as well as for a single Ln 3+ ion (La) with varying ligands (EDTA at pH ~7 and ~11). Changing the protonation state of an EDTA amine site significantly changes the solution structure of the Ln–EDTA complex resulting in a reduction of the complex stability. As a result, increased Ln–ligand complex stability is correlated to reduced structural variations in solution upon an increase in temperature.
The controlled functionalization of a single fluorine in a CF 3 group is difficult and rare. Photochemical C–F bond functionalization of the sp 3 -C–H bond in trifluorotoluene, PhCF 3 , is achieved using catalysts made from earth-abundant lanthanides, (Cp Me4 ) 2 Ln(2-O-3,5- t Bu 2 -C 6 H 2 )(1-C{N(CH) 2 N( i Pr)}) (Ln = La, Ce, Nd and Sm, Cp Me4 = C 5 Me 4 H). The Ce complex is the most effective at mediating hydrodefluorination and defluoroalkylative coupling of PhCF 3 with alkenes; addition of magnesium dialkyls enables catalytic C–F bond cleavage and C–C bond formation by all the complexes. Mechanistic experiments confirm the essential role of the Lewis acidic metal and support an inner-sphere mechanism of C–F activation. Computational studies agree that coordination of the C–F substrate is essential for C–F bond cleavage. The unexpected catalytic activity for all members is made possible by the light-absorbing ability of the redox non-innocent ligands. The results described herein underscore the importance of metal–ligand cooperativity, specifically the synergy between the metal and ligand in both light absorption and redox reactivity, in organometallic photocatalysis.
The synthesis and magnetic properties of two pairs of isomeric, exchange-coupled complexes, [LnCl 6 (TiCp 2 ) 3 ] (Ln = Gd, Tb), are reported. Magnetic exchange interactions and high local symmetry at the lanthanide ion are used to improve SMM behavior.
Correction for ‘Radiolabeling and in vivo evaluation of lanmodulin with biomedically relevant lanthanide isotopes’ by Kirsten E. Martin et al. , RSC Chem. Biol. , 2023, https://doi.org/10.1039/D3CB00020F.
Correction for ‘The solution structures and relative stability constants of lanthanide–EDTA complexes predicted from computation’ by Ravi D. O’Brien et al. , Phys. Chem. Chem. Phys. , 2022, 24 , 10263–10271, https://doi.org/10.1039/D2CP01081J.
We report the synthesis, crystal structures, photophysical and magnetic properties of 11 novel lanthanide complexes with the asymmetrically functionalized trispyrazolylborate ligand 4-nitrotrispyrazolylborate, 4-NO 2 Tp–: [Ln(4-NO 2 Tp) 3 ] (Ln = La–Dy, except Pm). In-depth photophysical characterization of the ligands via luminescence, reflectance and absorption spectroscopic techniques, decay lifetimes, quantum yields supported by time-dependent density functional theory (TD-DFT) and natural bond order (NBO) analysis reveal that n-NO 2 Tp– ligands are dominated by intra-ligand charge transfer (ILCT) transitions and that second-sphere interactions are critical to the stabilization of the T 1 state of n-NO 2 Tp– ligands and hence their ability to sensitize Ln 3+ emission. The luminescence properties of the complexes indicate that 4-NO 2 Tp– is a poor sensitizer of Ln 3+ emission, unlike 3-NO 2 Tp–. Moreover, [Nd(4-NO 2 Tp) 3 ] (crystallized as a hexane solvate) displays single-molecule magnet (SMM) properties, with longer relaxation times and larger barrier than the non-functionalized [NdTp 3 ], attributed to the addition of the NO 2 -group and subsequent rigidification of the molecular structure.
Here we describe the synthesis, structures, and volatility of lanthanide complexes containing N 4 O 3 ligands decorated with different fluoroalkyl substituents. The results show how ligand fluorination does not necessarily enhance complex volatility.
Correction for ‘Impact of lanthanide ion complexation and temperature on the chemical reactivity of N , N , N ′, N ′-tetraoctyl diglycolamide (TODGA) with the dodecane radical cation’ by Gregory P. Horne et al. , Phys. Chem. Chem. Phys. , 2023, 25 , 16404–16413, https://doi.org/10.1039/D3CP01119D.
Photon avalanche (PA)—where the absorption of a single photon initiates a ‘chain reaction’ of additional absorption and energy transfer events within a material—is a highly nonlinear optical process that results in upconverted light emission with an exceptionally steep dependence on the illumination intensity. Over 40 years following the first demonstration of photon avalanche emission in lanthanide-doped bulk crystals, PA emission has been achieved in nanometer-scale colloidal particles. The scaling of PA to nanomaterials has resulted in significant and rapid advances, such as luminescence imaging beyond the diffraction limit of light, optical thermometry and force sensing with (sub)micron spatial resolution, and all-optical data storage and processing. In this review, we discuss the fundamental principles underpinning PA and survey the studies leading to the development of nanoscale PA. Finally, we offer a perspective on how this knowledge can be used for the development of next-generation PA nanomaterials optimized for a broad range of applications, including mid-IR imaging, luminescence thermometry, (bio)sensing, optical data processing and nanophotonics.
The structural and vibrational properties of lanthanide Lindqvist (LnW 10 ) polyoxometalates were investigated to delineate the effects of structural changes and polymorphism on vibrational manifolds relevant to spin based relaxation processes.
Lanthanide reactivity is limited by the energy required to access an electronic configuration with two unpaired non-f electrons.
Correction for ‘Interfacial rheology of lanthanide binding peptide surfactants at the air–water interface’ by Stephen A. Crane et al. , Soft Matter , 2024, 20 , 9161–9173, https://doi.org/10.1039/D4SM00493K.