Stabilization of Tetrahedral P4 and As4 Molecules as Guests in Polymeric and Spherical Environments

As you like it: [Ag(η2‐As4)2]+[pftb]− can be used to store yellow arsenic (As4). From it, As4 can be easily released to give concentrated, light‐stable solutions. These As4 solutions, and those of white phosphorus (P4), allowed molecular As4 and P4 to be encapsulated inside giant, spherical aggregates and polymeric matrices, enabling the first determination of their EE (E=P, As) bond lengths by diffraction methods.