<p>The thermal stability of pseudocyclic and cyclic <i>N</i>-heterocycle-stabilized (hydroxy)aryl- and mesityl(aryl)-l<sup>3</sup>-iodanes (NHIs) through thermogravimetric
analysis (TGA) and differential
scanning calorimetry (DSC) is investigated. NHIs bearing <i>N</i>-heterocycles
with a high N/C-ratio such as triazoles show among the lowest descomposition temperatures and the highest decomposition energies. A comparison of NHIs with known (pseudo)cyclic benziodoxolones is made
and we further correlated their thermal stability with reactivity in a model
oxygenation. </p>
