Rational Design of Antimony-Based Zintl Clusters: Unveiling Unconventional Bonding and Architectures

ConspectusThe past decade has witnessed rapid growth in the synthesis of main-group element clusters, driven by advances in the design of Zintl phase precursors and their integration with organometallic reagents. These strategies have unlocked unprecedented structural motifs and bonding patterns, greatly enriching the landscape of main-group cluster chemistry. Among them, antimony-based clusters stand out for their diverse architectures and unique electronic properties, serving as ideal models to explore metalloid aromaticity, multicenter bonding, and unconventional Sb-Sb or Sb-metal interactions. Despite increasing interest in the functional potential of antimony clusters, their precise and controllable synthesis remains a major challenge. This is primarily due to poor precursor compatibility, complex reaction pathways with abundant byproducts, difficulties in efficiently isolating target clusters, and the lack of general synthetic strategies that enable systematic control over their unique geometric and electronic structures.Addressing these issues, we have developed a synthetic strategy based on the systematic reaction between inorganic antimony-based Zintl phase precursors and organometallic complexes. By optimally matching the reactivity of both components, this approach enables the construction of structurally novel antimony Zintl clusters. This methodology not only expands the accessible structural space but also enables the controlled generation of bonding patterns previously unseen in this class of compounds. Combined with theoretical analysis, our work reveals a range of nonclassical bonding modes─including multicenter interactions, novel metal-metal bonds, and aromatic stabilization effects─that redefine our understanding of bonding in main-group (metal) clusters. These findings not only broaden the conceptual framework of Zintl chemistry but also offer new opportunities to connect cluster structures with potential functional applications. Guided by the interplay of synthetic innovation and theoretical insight, main-group cluster chemistry is poised to evolve toward greater complexity and applicability.