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lanthanide-oxo clusters for efficient catalytic reduction of carboxamides

Science China Chemistry 2023年第2期66卷 443-448页

作者： Zhen-Zhang Weng Chao-Long Chen Long-Wu Ye La-Sheng Long Lan-Sun Zheng Xiang-Jian Kong Collaborative Innovation Center of Chemistry for Energy Materials State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of ChemistryCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen361005China

The reduction of carboxamides into high value-added amines is a very interesting but great challenging topic.Herein we demonstrate that polynuclear lanthanide-oxo clusters Ln16(Ln=Eu and Gd)can be used as efficient catalyst to reduce primary and secondary carboxamides to amines with excellent yield of 71%-98%and broad substrates scope.The methodology can extend to the gram-scale synthesis of phenethylamine drug with 93%yield.Based on the isolation and characterization of catalytic intermediates,a catalytic mechanism involving multipath reaction is proposed.This work provides efficient lanthanide cluster catalysts for the reduction of carboxamides to amines.

关键词： lanthanide clusters amide reduction metal-hydride BH3 catalytic mechanism

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Synthesis of two lanthanide clusters Ln^(Ⅲ)_(4)(Gd_(4) and Dy_(4)) with [2×2] square grid shape:Magnetocaloric effect and slow magnetic relaxation behaviors

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Journal of Rare Earths 2021年第9期39卷 1082-1088页

作者： Chunying Xu Zhilei Wu Chenjuan Fan Lili Yan Wenmin Wang Baoming Ji Henan Key Laboratory of Function-Oriented Porous Materials.College of Chemistry and Chemical Engineering Luoyang Normal UniversityLuoyang 471934China College of Chemistry and Environmental Science Hebei UniversityBaoding 071002China Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Nankai University.Tianjin 300071China

Two isostructural tetranuclear lanthanide clusters named [Ln_(4)(L)_(4)(CH_(3) O)_(4)]·CH_(3) OH(Ln=Gd(Ⅲ) for 1,Dy(Ⅲ) for 2,H_(2) L=N’-(2-hydroxy-3-methoxybenzylidene)-6-(hydroxymethyl) picolinohydrazide) were successfully isolated by using a polydentate Schiff based ligand and Ln(Ⅲ) nitrate salts.The structures of 1 and 2 were characterized by X-ray structural analyses,they are held by four double deprotonated ligands L2-.In them all the lanthanide ions are eight-coordinated and distributed over four vertices of a parallelogram,presenting a Ln4 cluster with a strict [2 × 2] square grid pattern.The details of magnetic analysis show that 1 displays weak anti-ferromagnetic exchange between neighboring Gd(Ⅲ) ions through carboxylate oxygen and methanol oxygen ligand atoms.Furthermore,1 exhibits significant magnetocaloric effect with the maximum entropy change-ΔSm value of 28.5 J/(kg K) for ΔH=7.0 T at 2.0 K.For compound 2,remarkable slow magnetic relaxation behaviors are observed in the presence of zero magnetic field with τ0=1.02 × 10^(-6) s and energy barrier ΔE/kB=43.24 K.

关键词： lanthanide clusters [2×2]square grid Anti-ferromagnetic couplings Magnetocaloric effect Slow magnetic relaxation Rare earths

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High-stability spherical lanthanide nanoclusters for magnetic resonance imaging

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National Science Review 2023年第4期10卷 123-132页

作者： Hai-Ling Wang Donglin Liu Jian-Hua Jia Jun-Liang Liu Ze-Yu Ruan Wei Deng Shiping Yang Si-Guo Wu Ming-Liang Tong Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education School of Chemistry Sun Yat-sen University College of Chemistry and Materials Science Shanghai Normal University

High-nuclear lanthanide clusters have shown great potential for the administration of high-dose mononuclear gadolinium chelates in magnetic resonance imaging(MRI). The development of high-nuclear lanthanide clusters with excellent solubility and high stability in water or solution has been challenging and is very important for expanding the performance of MRI. We used N-methylbenzimidazole-2-methanol(HL) and LnCl3·6H2O to synthesize two spherical lanthanide clusters, Ln32(Ln = Ho, Ho32; and Ln =Gd, Gd32), which are highly stable in solution. The 24 ligands L-are all distributed on the periphery of Ln32and tightly wrap the cluster core, ensuring that the cluster is stable. Notably, Ho32can remain highly stable when bombarded with different ion source energies in HRESI-MS or immersed in an aqueous solution of different pH values for 24 h. The possible formation mechanism of Ho32was proposed to be Ho(Ⅲ),(L)-and H2O → Ho3(L)3/Ho3(L)4→ Ho4(L)4/Ho4(L)5→ Ho6(L)6/Ho6(L)7→ Ho16(L)19→Ho28(L)15→ Ho32(L)24/Ho32(L)21/Ho32(L)23. To the best of our knowledge, this is the first study of the assembly mechanism of spherical high-nuclear lanthanide clusters. Spherical cluster Gd32, a form of highly aggregated Gd(Ⅲ), exhibits a high longitudinal relaxation rate(1 T, r1= 265.87 mM-1·s-1). More notably, compared with the clinically used commercial material Gd-DTPA, Gd32has a clearer and higher-contrast T1-weighted MRI effect in mice bearing 4T1 tumors. This is the first time that high-nuclear lanthanide clusters with high water stability have been utilized for MRI. High-nuclear Gd clusters containing highly aggregated Gd(Ⅲ) at the molecular level have higher imaging contrast than traditional Gd chelates; thus, using large doses of traditional gadolinium contrast agents can be avoided.

关键词： T1-weighted MRI lanthanide clusters high stability low toxicity assembly mechanism

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36-nuclearity lanthanide clusters as luminescent sensor

36-nuclearity lanthanide clusters as luminescent sensor

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中国化学会第八届全国配位化学会议

作者： Wenjing Wang Daqiang Yuan State Key Laboratory of Structure Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences

The synthesis of high-nuclearity pure lanthanide clusters continues to be a challenge because of the lanthanide ions have variable and high coordination numbers as well as poor directionality.Here,two isostructural{[Tb(NA)(OH)(O)(NO)(N)(H O)]Cl·28 H O}and{[Eu(NA)(OH)(O)(NO)(N)(H O)]Cl·28 H O}(HNA=nicotinic acid),which are analogous to reported Gd-and Dy-based clusters,have been synthesized and studied by single-crystal X-ray diffraction,el emental analysis,powder X-ray diffraction,IR spectra and TG Colorless crystals crystallize intricli nic space group PT.The photoluminescence results indicate that thenicotinic acid ligand can sensitize the Tb and Euions simultaneously.Thus,t hese two clusters could be u sed as luminescent sensors.

关键词： lanthanide clusters luminescent sensors

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Magnetic Properties of 3D Heptanuclear lanthanide Frame-works Supported by Mixed Ligands

Magnetic Properties of 3D Heptanuclear Lanthanide Frame-work...

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中国化学会第九届全国无机化学学术会议

作者： Falu Hu Mingyan Wu Feilong Jiang Maochun Hong State Key Laboratory of Structure Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of Sciences University of Chinese Academy of Sciences

Exploration of pure lanthanide clusters is one of the most important frontiers due to their charming and diverse structures as well as potential applications such as molecular magnets,imaging,luminescence and catalysis.As a result,a lot of pure lanthanide clusters have been documented.Up to now,many attempts have been made to the introduction of these polynuclear lanthanide clusters into the skeleton of polymer frameworks,while it is rarely realized.The main reason may be that high-nuclearity lanthanide clusters either are prevented from the further aggregation by big hydrophobic organic ligands or are surrounded by supporting ligands without further coordination sites.The mixed ligand system may be an effective approach to construct multidimensional lanthanide clusters based frameworks since mixed organic ligands may extend the structure through their different coordination conformations or sites.Herein,we report two new 3D frameworks constructed by heptanuclear lanthanide clusters and mixed bridging organic ligands,[Ln7（DPA）5（NA）3（μ3-OH）8（H2O）3]·2.5H2O（Ln=Gd（1）,Dy（2）;H2DPA=diphenic acid,HNA=nicotinic acid）.To the best of our knowledge,these are rarely-seen 3D lanthanide clusters based framework linked by two kinds of organic ligands.Interestingly,complex 1 possesses a large MCE of-ΔSm（T）=34.15 J kg-1 K-1.The above results indicate that the mixed-ligand strategy may be an efficient approach to construct mutidimensional frameworks with high-nuclearity Ln（Ⅲ）clusters.

关键词： lanthanide clusters Mixed ligands Magnetic properties

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Synthesis and Magnetic Properties of the Monodisperse lanthanide Metal Cluster

Synthesis and Magnetic Properties of the Monodisperse Lantha...

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中国化学会第八届全国配位化学会议

作者： Xiu-Ying Zheng Xiang-Jian Kong La-Sheng Long Lan-Sun Zheng Collaborative Innovation Center of Chemistry for Energy Materials State Key Laboratory of Physical Chemistry of Solid Surface and Department of Chemistry Xiamen University

High-nuclearity cluster-type metal complexes are a unique class of compounds exhibiting not only aesthetically pleasing molecular structures but also interesting physical and chemical properties arising primarily from the electronic and/or magnetic interplay between the component metal ions.Recently,significant research interest has been devoted to nano-size,single-molecule metal clusters,because the monodisperse metal clusters provide a unique platform for investigating magnetic exchange within molecule magnets.In an effort to isolate such single-molecule metal clusters,several synthetic strategies have been developed.For example,individual single-molecule magnets(SMMs) Mn have been dispersed on the surface of a polymeric thin film,the surface of Au(111),or incorporated into metal-organic frameworks(MOF) or carbon nanotubes.We have also made some preliminary attempts at creating processible and practically useful materials in the form of monodisperse core-shell nanostructure.We succeeded in encapsulating only one nano-sized heterometallic molecular cluster into a nanoshell of silica.It has been found that such passivation not only helped stabilize the cluster,but also reduced the magnetic interactions between individual clusters.

关键词： lanthanide clusters Magnetic Properties single-molecule monodisperse core-shell

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