Hexalanthanide Complexes as Molecular Precursors: Synthesis, Crystal Structure, and Luminescent and Magnetic Properties

Abstract

Reaction of hexanuclear octahedral molecular precursors with a 3-chlorobenzoate ligand affords an unprecedented family of isostructural polylanthanide complexes via solvothermal and microwave-assisted syntheses in an acetonitrile medium. The general chemical formula of the compounds that constitute this series is {[Ln(μ-OH)(HO)(NO)(3-cb)]·(CHCN)}, where 3-cb stands for 3-chlorobenzoate and Ln = Eu, Tb, Dy, Ho, Er, or Y. The crystal structure, solubility, and magnetic and luminescent properties of these complexes have been studied. The luminescent properties evidence that the composition of the hexalanthanide precursor is preserved during the synthetic process that is of particular interest for cases in which heterolanthanide complexes are targeted.

Hexanuclear Molecular Precursors as Tools to Design Luminescent Coordination Polymers with Lanthanide Segregation

“…It was previously shown for a similar system that carboxylate oxygen atom binding and collapse of the starting hexanuclear complex occur simultaneously. Indeed, the carboxylate functions clip and connect neighboring lanthanide ions, while the capping hydroxyl groups are removed.…”

“…However, to date, the only polylanthanide complexes stable enough to act as molecular precursors are hexanuclear complexes with a [Ln 6 (μ 6 -O)(μ 3 -OH) 8 ] 8+ core, first described by Zak et al (Figure 2). When these octahedral complexes are used as molecular precursors, they can lead to coordination polymers, 45 complexes, 58,59 or colloidal suspensions. 60 During the synthetic process, the octahedral arrangement is more or less modified, 45,58,59 depending on the synthesis.…”

“…When these octahedral complexes are used as molecular precursors, they can lead to coordination polymers, complexes, , or colloidal suspensions . During the synthetic process, the octahedral arrangement is more or less modified, ,, depending on the synthesis.…”

“…When these octahedral complexes are used as molecular precursors, they can lead to coordination polymers, complexes, , or colloidal suspensions . During the synthetic process, the octahedral arrangement is more or less modified, ,, depending on the synthesis. However, even when the hexanuclear core is destroyed, hexanuclear complexes used as reactants present a structuring effect and lead to original crystal structures that cannot be obtained using mononuclear lanthanide salts. , It can be noticed that, in this octahedral core, lanthanide ions are about 3.5 Å far from each other, which is close to the distance between two lanthanide ions bridged by a carboxylate group.…”

Half‐Sandwich Complexes [Cp′4Ln4I8]4 (Ln=Ce, Pr):Emergence of Donor‐Free Organolanthanide Nanowheels

“…[1][2][3][4][5][6][7][8][9][10][11][12][13] While organolanthanide clusters assist in unravelling the active species of industrial 1,3-diene polymerization catalysis, [14] luminescent coordination clusters do impress with intriguing structural motifs and bright colors. [8,10,13,[15][16][17][18][19][20] As for cerium(III) (4 f 1 ), the photoluminescent properties are determined by dipole-allowed 5 d!4 f transitions, which enables efficient tuning of the emission wavelength of complexes. [21][22][23] This effect can be further enhanced in terms of the luminescence intensity in combination with a variety of ligand systems, including cyclopentadienyl derivatives [24] or hydridotris(pyrazolyl)borato ligands, [25] given their stabilizing properties.…”