Key Lab of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P.R. China.
Nanoscale. 2018 Nov 7;10(41):19375-19382. doi: 10.1039/c8nr03700k. Epub 2018 Oct 11.
Atomically precise metal clusters stabilized by organic ligands have attracted extensive interest, and these monodisperse clusters have particular potential for providing insights into puzzling areas of heterogeneous catalysis such as inherent size polydispersity. In many traditional catalytic reactions, however, the reactivity of metal clusters is frequently found to be passivated, where the active sites on the surface metal atoms are blocked by the ligand molecules. Therefore, of particular interest are studies that involve triggering the catalytic ability of metal clusters, with no need to remove any ligands, via thermal treatments that usually destroy their atomically precise structures. Herein, with the determination of the structure of Ni(SR) (where SR denotes thiolate), where Ni atoms are fully coordinated with the thiolate molecules, the catalytic activity of Ni(SR) for nitriles hydrogenation toward primary amines could be significantly enhanced with the assistance of NH molecules that positively suppress the ligand-shielding effect.
由有机配体稳定的原子精确金属簇引起了广泛关注，这些单分散的金属簇在深入了解多相催化等令人费解的领域方面具有特殊的潜力，例如固有尺寸多分散性。然而，在许多传统的催化反应中，金属簇的反应性经常被发现被钝化，即表面金属原子上的活性位被配体分子所封锁。因此，特别有趣的是那些通过热解处理来触发金属簇的催化能力的研究，而无需去除任何配体，通常这种热解处理会破坏它们原子精确的结构。在此，通过 Ni(SR)（其中 SR 表示硫醇盐）结构的确定，Ni 原子与硫醇盐分子完全配位，在 NH 分子的辅助下，Ni(SR)对腈类向伯胺的氢化作用的催化活性可以显著增强，NH 分子可以积极抑制配体屏蔽效应。
