化学
催化作用
配体(生物化学)
路易斯酸
沮丧的刘易斯对
电泳剂
组合化学
反键分子轨道
芳基
产量(工程)
钯
选择性
计算化学
立体化学
光化学
金属
纳米材料基催化剂
路易斯酸催化
配位复合体
磷化矿
反应速率
过渡金属
纳米颗粒
作者
Qinggang Zhang,Jing Li,Jie Chen,Yongsheng Ma,Canfeng Lin,Yun Bai,Zhonggao Zhou,Chun-Ting He,Baolei Li,Yuehua Chen
标识
DOI:10.1021/acscatal.6c01832
摘要
Deliberately engineering frustrated Lewis pairs (FLPs) on nanocatalysts provides an effective approach for small-molecule activation, yet catalytic performances remain constrained by imprecise ligand coordination sites. Herein, we proposed a crab-like coordination paradigm to stabilize palladium nanoparticles (PdNPs) through designing multi-acetylated ligands. Specifically, 2-methylimidazolium units with varying positional substitutions, bearing acetylglucose groups (AcGlu), were synthesized to chelate PdNPs, resulting in a series of FLP catalysts featured with surface Pd atoms as Lewis acids and in situ -generated N -heterocyclic olefins (NHOs) as Lewis bases. Combined with a kinetic framework integrating calibrated experimental data with industrial simulations, the SISSO method was used to identify key rate descriptors; the NHO···Pd FLP catalyst 1c (2.3 ± 0.3 nm) delivers high yield and selectivity and achieves a turnover frequency of 1107 h −1 in carboxylative cyclization and cross-coupling tricomponent reactions of propargylic amines, aryl iodides, and dilute CO 2 . Combined experimental and spectroscopic investigations reveal that 1c effectively captures and dynamically activates CO 2 through AcGlu−CO 2 philes and NHO−CO 2 adducts. The donation into the antibonding orbital of CO 2 facilitates back-electron transfer from C to O atoms, weakening the CO bond and lowering the activation barrier for its cleavage, thus enabling a kinetically favorable electrophilic addition that accounts for the enhanced catalytic performance. These findings demonstrate that precisely ligand-engineered metal NPs provide an effective platform for FLP architectures toward the dynamic activation and multicomponent conversion of dilute CO 2 .
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