Recent advances in the stabilization of monomeric stibinidene chalcogenides and stibine chalcogenides

Abstract

The elucidation of novel bonding situations at heavy p-block elements has greatly advanced recent efforts to access useful reactivity at earth-abundant main-group elements. Molecules with unsaturated bonds between heavier, electropositive elements and lighter, electronegative elements are often highly polarized and competent in small-molecule activations, but the reactivity of these molecules may be quenched by self-association of monomers to form oligomeric species where the polar, unsaturated groups are assembled in a head-to-tail fashion. In this Frontier, we discuss the synthetic strategies employed to isolate monomeric σ²,λ³-stibinidene chalcogenides (RSbCh) and monomeric σ⁴,λ⁵-stibine chalcogenides (R₃SbCh). These classes of molecules each feature polarized antimony–chalcogenide bonds (Sb = Ch/Sb⁺–Ch⁻). We highlight how the synthesis and isolation of these molecules has led to the discovery of novel reactivity and has shed light on fundamental aspects of inorganic structure and bonding. Despite these advances, there are critical aspects of this chemistry that remain underdeveloped and we provide our perspective on yet-unrealized synthetic targets that may be achieved with the continued development of the strategies described herein.