Formation and selection of the macrocycle [{(tBuN=)P(μ-NtBu)}2(μ-Se)2{P(μ-NtBu)}2]3

Main group inorganic macrocycles, based on p-block element backbones other than carbon, are a challenging synthetic target that has been largely overlooked. In this study, we show that a simple strategy based on the combination of electrophilic and nucleophilic phosphazane building blocks can be extended to readily accessible [E(Bu-t=N)P(mu-(NBu)-Bu-t)](2)(2-) nucleophilic components, as exemplified by the Se-bridge P-III/P-V phosphazane macrocycle [{((BuN)-Bu-t=)P-V(mu-(NBu)-Bu-t)}(2)(mu-Se)(2){P-III(mu-(NBu)-Bu-t)}(2)](3).