Bistelluridopnictanes as gateways to telluradipnictiranes and a cyclic [Bi2Te2]2+ dication.

The controlled assembly of molecular pnictogen-tellurium (Pn-Te) frameworks remains a longstanding synthetic challenge due to the intrinsic lability of Pn-Te bonds, particularly of the heaviest pnictogens, resulting in a scarcity of well-defined compounds. Here we present a general synthesis strategy that enables reliable access to a homologous series of bistelluridopnictanes DMPPn(TePh)2 (Pn = As (1), Sb (2), Bi (3); DMP = 2,6-Mes2C6H3, Mes = 2,4,6-Me3C6H2), providing a systematic platform for comparing structure, bonding, and reactivity across the heavier pnictogens. Comprehensive spectroscopic (1H, 13C, 125Te NMR, IR) and crystallographic studies (sc-XRD) reveal clear periodic trends in Pn-Te interactions and coordination geometries. Decomposition experiments uncover a unified initial reductive elimination of diphenylditelluride (Ph2Te2), followed by consecutive pnictogen-dependent follow-up reactions including the formation of dipnictenes and three-membered telluradipnictiranes, respectively. Our studies finally resulted in the isolation of the first telluradiarsirane DMPAs(µ-Te)AsDMP (4) and very rare examples of the corresponding Sb and Bi congeners DMPPn(µ-Te)PnDMP (Pn = Sb (5), Bi (6)). The attempted synthesis of cationic species by reaction of compounds 1-3 with silver triflate yielded [DMPBi(TePh)]2[SbF6]2 (7) containing an unprecedented dicationic Bi2Te2 four-membered heterocycle, representing the first mixed Bi-Te analogue of a structural motif previously restricted to lighter and homonuclear pnictogen systems. Our findings expand the accessible chemical space of heavy pnictogen-tellurium compounds, illuminate fundamental trends in bonding and reactivity, and provide a modular entry point toward tailored molecular precursors for chalcogenide materials and advanced main-group architectures.