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Two five‐coordinate mononuclear DyIII single‐molecule magnets [(TrapenTMS)Dy(L)] (Trapen=tris(2‐aminobenzyl) amine; TMS=SiMe3; L=OPMe31, OPEt32) have been synthesized by the reaction of [(TrapenTMS)Dy(THF)] and OPMe3, OPEt3, respectively. The molecular structures of 1 and 2 were fully established by single crystal X‐ray diffraction. The centre DyIII ions of both complexes exhibit distorted triangular bipyramid geometries, varying with different neutral ligands L on the apex. The TrapenTMS ligand forms the pyramid base of the trigonal bipyramid. Subtle structural modifications of the axial O‐ligand terminal substituent result in different dynamic magnetic behaviors. Magnetic data analysis reveals that 1 and 2 exhibit the characteristic behavior of SMM without a dc field, accompanying an unambiguous quantum tunneling of the magnetization. Field‐induced slow magnetic relaxation was observed for 1 and 2 under an applied bias dc field of 1000 Oe, the relaxation energy barriers are 107 K and 88 K for 1 and 2, respectively. We have investigated the differences in magnetism and magnetic anisotropy between the two complexes by ab initio calculations. [ABSTRACT FROM AUTHOR]

A new family of low-coordinate mononuclear DyIII single-molecule magnets [(TrapenTMS)Dy(LB)] (Trapen = tris(2-aminobenzyl)amine; TMS = SiMe3; LB = THF 1, pyridine 2, ONMe33) has been synthesized and structurally characterized by single crystal X-ray diffraction. The five-coordinate DyIII ions exhibit distorted triangular bipyramidal geometries, among the different neutral ligands LB on the apex and the same TrapenTMS ligand, making the pyramid base of the trigonal bipyramid. Magnetic data analysis reveals that 1–3 are characteristic of SMM behaviors without a dc field, accompanying an unambiguous quantum tunneling of magnetization. Under an extra dc field of 500 Oe, field-induced slow magnetic relaxation behaviors occur with Raman and/or QTM processes. Ab initio calculations were also performed to rationalize the observed discrepancy in the magnetic behaviors, and the result illustrates that the SMM behavior could be effectively manipulated by the axial symmetry of the triangular bipyramidal DyIII motifs. [ABSTRACT FROM AUTHOR]

Although synthesis, reactivity, and bonding of U(IV) and Th(IV) complexes have been extensively studied, direct comparison of fully analogous compounds is rare. Herein, we report corresponding complexes 1-U and 1-Th , in which U(IV) and Th(IV) are supported by the tetradentate pyridine-decorated dianionic ligand N 2 NN' (1,1,1-trimethyl- N -(2-(((pyridin-2-ylmethyl)(2-((trimethylsilyl)amino)benzyl)amino)methyl)phenyl)silanamine). Although 1-U and 1-Th are structurally very similar, they display disparate reactivities with TMS 3 SiK (tris(trimethylsilyl)silylpotassium). The reaction of (N 2 NN')UCl 2 ( 1-U ) and 1 equiv of TMS 3 SiK in THF unexpectedly formed [Cl(N 2 NN')U] 2 O ( 2-U ) featuring an unusual bent U-O-U moiety. In contrast, a salt elimination reaction between (N 2 NN')ThCl 2 ( 1-Th ) and 1 equiv of TMS 3 SiK led to thorium complex 2-Th , in which the pyridyl group has undergone a 1,4-addition nucleophilic attack. Complex 2-Th serves as a synthon for preparing dimetallic bis-azide complex 3-Th by reaction with NaN 3 . The complexes were characterized by X-ray crystal diffraction, solution NMR, FT-IR, and elemental analysis. Computations of the formation mechanism of 2-U from 1-U suggest reduced U(III) as a key intermediate for promoting the cleavage of the C-O bonds of THF. The inaccessible nature of Th(III) as an intermediate oxidation state explains the very different reactivity of 1-Th versus 1-U . Given that reactants 1-U and 1-Th and products 2-U and 2-Th all comprise tetravalent actinides, this is an unusual case of very disparate reactivity despite no net change in the oxidation state. Complexes 2-U and 3-Th provide a basis for the synthesis of other dinuclear actinide complexes with novel reactivity and properties.

A new family of low-coordinate mononuclear Dy III single-molecule magnets [(Trapen TMS )Dy(L B )] (Trapen = tris(2-aminobenzyl)amine; TMS = SiMe 3 ; L B = THF 1, pyridine 2, ONMe 3 3) has been synthesized and structurally characterized by single crystal X-ray diffraction. The five-coordinate Dy III ions exhibit distorted triangular bipyramidal geometries, among the different neutral ligands L B on the apex and the same Trapen TMS ligand, making the pyramid base of the trigonal bipyramid. Magnetic data analysis reveals that 1-3 are characteristic of SMM behaviors without a dc field, accompanying an unambiguous quantum tunneling of magnetization. Under an extra dc field of 500 Oe, field-induced slow magnetic relaxation behaviors occur with Raman and/or QTM processes. Ab initio calculations were also performed to rationalize the observed discrepancy in the magnetic behaviors, and the result illustrates that the SMM behavior could be effectively manipulated by the axial symmetry of the triangular bipyramidal Dy III motifs.

Herein we present a new metalloligand, Th 6 L 12 [IHEP-10; L = 4-pyrazolecarboxylic acid (H 2 PyC)], which can be used to generate a novel multicomponent heterometallic metal-organic framework (MOF), [[Cu 3 (μ 3 -OH)(NO 3 )(H 2 O) 2 ] 2 Th 6 (μ 3 -O) 4 (μ 3 -OH) 4 (PyC) 6 (HPyC) 6 (H 2 O) 6 ](NO 3 ) 2 (IHEP-11), through further assembly with second [Cu 3 (μ 3 -OH)(PyC) 3 ] clusters. In IHEP-11, six Cu 3 clusters are connected by six NO 3 - anions to form an unprecedented annular Cu 18 cluster, which can be viewed as a 12-connected node to link with 12 Th 6 clusters, resulting a 4,12-connected shp net. Benefiting from the cationic framework and 3D porous structure, IHEP-11 can efficiently remove ReO 4 - (an analogue of radioactive 99 TcO 4 - ) from aqueous solution in a wide pH range. This work highlights the feasibility of constructing multicomponent MOFs through a step-by-step synthesis strategy based on metalloligands.