A series of mixed valence hexanuclear dicationic coordination clusters containing two µ₄‐O^2– bridges with general formula M²⁺(X^–)₂ [M = Ce^IV₂Ce^III₄(µ₄‐O)₂(L–R)₄(val)₆(H₂O)₂; 1²⁺, 3²⁺: R = H, 2²⁺: Me; 1²⁺, 2²⁺: X = Ce^III₂(val)₃(NO₃)₄, 3²⁺: X = NO₃] were synthesized, isolated and characterized. The reaction of cerium(III)nitrate hexahydrate with Schiff base ligand (H₂L–R) and o‐vanillin (val‐H) under basic condition led to the formation of M²⁺(X^–)₂ and the reaction progress was monitored by mass spectrometric studies. The molecular structures of all complexes were unambiguously characterized by single‐crystal X‐ray diffraction. The magnetic susceptibility measurements of M²⁺(X^–)₂ showed that the Ce(III) ions are weakly antiferromagnetically coupled. Thermal stability and molar conductivity of M²⁺(X^–)₂ were also studied. Complex 3²⁺(X^–)₂ was further studied by X‐ray photoelectron spectroscopy to confirm the oxidation states of Ce(III/IV) ions. The M²⁺ cation was shown to catalyze the TEMPO‐free oxidation of functionalized benzyl alcohols quantitatively to the corresponding benzaldehyde derivatives at 100 °C in presence of aerial O₂ using DMF as the solvent.

中文翻译：

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氧化还原活性六核混合价阳离子Ce（III）/ Ce（IV）配位簇

一系列含有两个μ混合价六核双阳离子协调集群₄ -O ^2-桥与通式中号²⁺（X ^- ）₂ [中号=铈^IV ₂的Ce ^III ₄（μ ₄ -O）₂（L-R）₄（val）₆（H ₂ O）₂；1 2 ⁺，3 ²⁺：R = H，2 ²⁺：Me; 1 2 ⁺，2 ²⁺：X = Ce ^III ₂（VAL）₃（NO ₃）₄，3 ²⁺：X = NO ₃ ]合成，分离和表征。硝酸铈（III）六水合物与席夫碱配体（H ₂ L–R）和邻香兰素（val–H）在碱性条件下的反应导致M ²⁺（X ^–）₂的形成，反应进展为通过质谱研究进行监控。所有配合物的分子结构均通过单晶X射线衍射明确表征。M ²⁺（X ^–）_2的磁化率测量结果表明Ce（III）离子弱反铁磁耦合。热稳定性和的摩尔电导率中号²⁺（X ^- ）₂也进行了研究。X射线光电子能谱进一步研究了络合物3 ²⁺（X ^–）₂，以确认Ce（III / IV）离子的氧化态。结果表明，在100°C的空气中O ₂存在下，使用DMF作为溶剂，M ²⁺阳离子可以定量催化官能化的苄醇无TEMPO氧化成相应的苯甲醛衍生物。