Thermal Decomposition of Iodine Complexes with Pyridine

Experiments are performed on the interaction between iodine and pyridine in the 1:1 ratio under different conditions. Temperature dependences of the vapor pressure are measured in the I2–pyridine (py) system by the static tensimetric technique with a membrane null-manometer in the temperature range of 0-300 °C. Based on the analysis of the obtained results and the identification of the products formed by mass spectrometry, IR spectroscopy, and powder X-ray diffraction, schemes are proposed for the processes occurring upon heating. The crystal structure of the ${{[\text{pypy}]}^{+}}\text{I}_{3}^{-}$ compound is determined for the first time by single crystal X-ray diffraction.