Themed collection Rare Earth Chemistry – In memory of Professor Xu Guangxian at his centenary

Song Gao introduces the Inorganic Chemistry Frontiers themed collection in memory of Professor Xu Guangxian on his 100^th birthday.

Rare-earth-elements-based oxide ion conductors with various structures and their structure-property relationships were systematically presented and summarized, which can provide new insight and guidance for the development of new oxide ion conductors.

In this review, we summarize the nanostructural engineering and applications of rare earth oxide-based nanomaterials with well-defined compositions, crystal phases and shapes for efficiently catalyzing C1 chemical reactions.

The magnetic relaxation of lanthanide single-molecule magnets (Ln-SMMs) can be modulated reversibly by external stimuli including light irradiation, thermal treatment, protonation/deprotonation and oxidation/reduction etc.

The recent developments and prospects of near-infrared molecular probes based on luminescent lanthanide coordination complexes in bioimaging are described, which is important to emphasise the importance of lanthanide chemical biology.

The synthesis procedure of the N-doped PC-CDs composite and the electrochemical reaction of iodide at the PC-CDs surface.

An unprecedented series of salophen-bridged rare earth metallocenes, (Cp*₂RE)₂(μ-^tBusalophen) (RE = Gd, Dy, and Y), has been crystallized. The solid and solution states have been unambiguously characterized by magnetic, spectroscopic and DFT methods.

Homoleptic tris(bipy) rare earth metal complexes were synthesized and structurally characterized. While two parallel bipy radical anions were strongly antiferromagnetically coupled, the remaining bipy radical anion hosted most spin densities.

A dimeric yttrium phenoxide complex can be oxidized in a stepwise fashion to access three oxidation states. The three states show different activity in the ring opening polymerization of cyclic esters and epoxides.

Homoleptic yttrium and lanthanum complexes of bis(phosphineoxide) methanides, RE(H^PhL)₃ and RE₂(H^MeL)₆, promote the first rare-earth mediated Horner-Wittig and acid-base chemistry consistent with multifunctional reactivity (Lewis-acid/Brønstedbase).

Glutarimide-dioxime, a proligand known for its strongly electron-donating properties that has been studied for applications in uranium-sequestration from seawater, is considered here for stabilization of the cerium(IV) cation.

The reaction of a nickel complex bearing a redox-active dissymmetric ligand (Kbimpm) with a divalent lanthanide complex, Cp*₂Yb(OEt₂) affords an unprecedented, trimeric complex with C(sp³)–C(sp³) bond formation between two ligands in an exo position.

The routes for the optimization of the magnetic properties of rare earth permanent magnetic nanostructures are discussed, i.e. the control of microstructure, such as size and shape as well as the exchange-coupling interactions.

Controlled hydrolysis of lanthanide ions in the presence of histidine and halide templates of different sizes produced dodeca- and pentadecanuclear lanthanide hydroxide clusters.

Electron deficient scandium cyclopropyl complexes have been synthesized and fully characterized for the first time, and a combination of solid XRD, solution NMR and theoretical studies well demonstrated the α-C–C agostic interactions in the complexes.

The polymerization mechanism of methyl methacrylate (MMA) catalyzed by rare-earth/phosphorus (RE/P) Lewis pairs has been systematically studied through density functional theory (DFT) calculations.

Eu(II) complexes with high air stability and tunable emission colors were synthesized and characterized.

Two structural types of iridium(III)–lanthanide(III) coordination polymers, single-chain Ir₂Ln and double-chain Ir₄Ln₂ (Ln = Gd, Dy, Er, and Yb), have been prepared. SMM behaviour and NIR luminescence were observed for the Ir–Er and Ir–Yb systems.

Crystal structures demonstrate that 2.2.2-cryptand can function as a κ²-O,O′ bidentate ligand to rare-earth metal ions.

Ten air-stable dysprosium(III) SMMs with destroyed pentagonal-bipyramidal geometry imposed by axial bidentate-chelating pyrazolate ligands are studied, showing substitutional effect on axial ligands and no effect on equatorial ligands.

Three isostructural 3d–4f polynuclear clusters {(Ln^III₆Co^II₆)(C8A)₃} (Ln = Y, Eu, Dy; C8A = p-tert-butylcalix[8]arene) feature some tripod-like entities in which three Ln₂-C8A SBUs bolster a [Co₆] hexagon.

A terbium complex Tb-1 was demonstrated to undergo bioorthogonal ligation with engineered cell-surface glycans, which results in a much less efficient LRET and a 5-fold increase in long-lived terbium emission with low toxicity.

Multi-frequency EPR spectra and CASSCF-SO calculations on two symmetric homo-dimetallic lanthanide complexes are used to determine the magnetic exchange coupling in the low-lying states.

Synthesizing functional butadiene–styrene rubber through coordination polymerization is a theoretical challenge for polymer science, since functional monomers usually deactivate to the applied catalysts.

Utilizing the S = 7/2 4f spin and the D₄ symmetry of a Gd(III) complex, we propose and demonstrate an eight-leveled rare-earth molecular qudit, which can be coherently manipulated between adjacent energy levels with precompiled pulse durations.

The reduction of Ln(III)-trensal complexes allows to store electrons, that become available for CO₂ reduction, trough the formation of new C–C bonds.

A terbium metal–organic framework was synthesized for highly sensitive nitrite detection. The mechanism of the quenching process was also studied in detail.

A perfect triangular Dy₃ single-molecule magnet was reported. Each Dy(III) magnetic axis is oriented almost normal to the plane of Dy₃, and the intramolecular magnetic dipole interaction gives rise to a virtually antiparallel Ising-like ground state.

Narrow-band blue-emitting MBe₂(PO₄)₂:Eu²⁺ (M = Ca, Sr) phosphors were developed via selection of an ordered host with confined doping sites.

The first example of unique coordination induced intramolecular pancake bonding was achieved through the reduction of two bis(pyrazolyl)-tetrazine ligands.