Organostibanes

Organostibanes are organometallic compounds containing carbon–antimony bonds. They include trialkylstibanes (R3Sb), triarylstibanes (R3Sb), and lower-coordinate derivatives such as R2SbH and R3SbH. In these compounds, antimony is typically in the +3 oxidation state and bears a stereochemically active lone pair, giving a pyramidal geometry. C–Sb bonds are polar and variably covalent; many organostibanes are air- or moisture-sensitive and prepared under inert atmosphere.

Common preparation involves forming Sb–C bonds from organolithium or Grignard reagents with antimony halides, such as SbCl3, followed by workup to give R3Sb. Other routes include metathesis of organostibate precursors or reductive coupling of aryl halides with stibines. Hydrostibination of unsaturated substrates with H–SbR2 reagents is another route to organostibanes.

Reactivity and applications: The lone pair on Sb makes organostibanes Lewis-basic and capable of binding to Lewis acids or coordinating to transition metals, enabling their use as ligands in catalysis. The C–Sb bond can undergo oxidation, halogenation, or transmetallation under appropriate conditions to give higher-valent antimony species or new organoantimony derivatives. Organostibanes serve as building blocks in organic synthesis and materials chemistry, but they are less developed than analogous organosilicon compounds due to toxicity and handling challenges.

Safety: Antimony compounds are toxic; organostibanes pose inhalation, ingestion, and dermal hazards. They are typically handled under inert atmosphere with proper ventilation and protective equipment.