Complexes of group 13 element perfluorinated derivatives E(C₆F₅)₃ (E = Al, Ga, In) with pyridine (Py) were synthesized and structurally characterized for the first time. Volatility and thermal stability of complexes was studied using mass-spectrometry, tenzimetry, TGA, and drop-calorimetry methods. Heating of complexes results in elimination of pentafluorobenzene, indicating E-C bond rupture. Thermodynamic characteristics of gaseous complexes and transition states for C₆F₄, HF and C₆F₅H elimination were obtained using quantum chemical methods. Possible mechanisms for the thermal decomposition of complexes are proposed on the basis of experimental and computational data.