The controlled synthesis and exploration of the biomass valorization properties of organo-functionalized ionic-type polyoxometalates has been attracting considerable interest, but it still poses a challenge. Herein, three imidazole-functionalized ionic-type Pd-polyoxovanadates, [Pd(eIM)][VO(eIM)] (), [Pd(mIM)](HVO)·3HO () and [Pd(mIM)](VO)·4HO () (mIM = 1-methylimidazole, eIM = 1-ethylimidazole) with [VO(eIM)], [HVO] and [VO] clusters were skillfully designed and successfully isolated, respectively. Importantly, represents the first ionic-type combination of a Pd-complex with an organo-functionalized {VO(eIM)} cluster, and it exhibits remarkable catalytic activity towards the aerobic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF), achieving an impressive conversion of 93 % and selectivity of 98 % under atmospheric O. It can be reused at least five times without any loss of activity. Control experiments confirm that such exceptional catalytic activity originate from the cooperative effect between Pd-complex and {VO(eIM)}. Based on spectroscopic results and density functional theory calculations, a plausible mechanism involving two parallel pathways has been proposed.

中文翻译：

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合理制备三种咪唑功能化离子型多氧钒酸钯，用于 5-羟基甲基糠醛有氧氧化生成 2,5-二甲酰呋喃

有机功能化离子型多金属氧酸盐的生物质增值特性的受控合成和探索引起了人们极大的兴趣，但仍然提出了挑战。本文中，三种咪唑官能化离子型钯多钒酸盐，[Pd(eIM)][VO(eIM)] ()、[Pd(mIM)](HVO)·3HO () 和 [Pd(mIM)](VO )·4HO () (mIM = 1-甲基咪唑, eIM = 1-乙基咪唑) 与[VO(eIM)]、[HVO] 和[VO] 簇经过巧妙设计并分别成功分离。重要的是，代表了 Pd 配合物与有机功能化 {VO(eIM)} 簇的第一个离子型组合，它对 5-羟甲基糠醛 (HMF) 有氧氧化成 2,5-二甲酰呋喃表现出显着的催化活性(DFF)，在大气 O 下实现了 93% 的令人印象深刻的转化率和 98% 的选择性。它可以重复使用至少五次，而不会损失任何活性。对照实验证实，这种特殊的催化活性源于 Pd 络合物和 {VO(eIM)} 之间的协同效应。基于光谱结果和密度泛函理论计算，提出了涉及两个平行路径的合理机制。