The isolation of binary As‐N and ternary As‐N‐P cage compounds consisting exclusively of group 15 elements was achieved by exploiting the reactivity of diarsadiazanediyl. This arsenic centered biradical is capable of activating and/or quenching small molecules bearing double bonds such as diazenes, Ph‐N=N‐Ph, or in situ generated labile diphosphenes, e.g. Ph‐P=P‐Ph, leading to the formation of hexapnicta‐[2.1.1]bicyclohexanes.