Very sensitive materials: Tellurium tetraazide, Te(N3)4, was prepared directly from TeF4 and Me3SiN3 as an extremely sensitive solid; azidation of a pentafluorotellurate(IV) anion gave the pentaazidotellurate(IV) anion. The crystal structure of the pyridinium salt [pyH][Te(N3)5] consists of [Te(N3)5]− units, considerably distorted from ideal square‐pyramidal symmetry, that are linked through Te⋅⋅⋅N interactions (see picture).