Thiacalix[4]arene Etching of an Anisotropic CuH Intermediate for Accessing Robust Modularly Assembled Copper Nanoclusters.

Atom-precise metal nanoclusters (NCs) with large bulk (nuclearity >60) are important species for insight into the embryonic phase of metal nanoparticles and their top-down etching synthesis. Herein, we report a metastable rod-shaped 70-nuclei copper-hydride NC, [Cl@CuH(PhC≡C)(CFCOO)] (), with Cl as the template, in which the Cl@Cu kernel adopts a distinctive metal packing mode along the bipolar direction, and the protective ligand shell exhibits corresponding site differentiation. In terms of metal nuclearity, is the largest alkynyl-stabilized Cu-hydride cluster to date. As a typical highly active intermediate, could undergo a transformation into a series of robust modularly assembled Cu clusters (-type , -type , -type , and -type ) upon etching by --butylthiacalix[4]arene (HTCA), which could not be achieved by "one-pot" synthetic methods. Notably, the patterns of and blocks in the Cu NCs could be effectively modulated by employing appropriate counterions and blockers, and the modular assembly mechanism was illustrated through comprehensive solution chemistry analysis using HR-ESI-MS. Furthermore, catalytic investigations reveal that could serve as a highly efficient catalyst for the cycloaddition of propargylic amines with CO under mild conditions. This work not only enriched the family of high-nuclear copper-hydride NCs but also provided new insights into the growth mechanism of metal NCs.