Gas Phase Composition and Vaporization Thermodynamics of Cobalt(II) Pivalate Complexes

Resumo

Vaporization of cobalt(II) pivalate [Co(Piv)₂] (1, HPiv = HO₂CCMe₃) and cobalt(II) oxopivalate [Co₄O(Piv)₆] (2) complexes has been studied by Knudsen effusion technique in combination with mass-spectral analysis of gas phase composition. The congruent sublimation of the prepared compounds has occurred, it has been accompanied by partial thermal decomposition in the case of complex 1. Saturated vapor over complex 1 has been found to consist mainly of monomeric Co(Piv)₂, dimeric Co₂(Piv)₄, and small amount of tetrameric Co₄(Piv)₈ molecules, as well as Co₄O(Piv)₆, CO₂, and 2,2,4,4-tetramethylpentanone ones. Saturated vapor over complex 2 contains only Co₄O(Piv)₆ species. The absolute values of partial pressure and sublimation enthalpies of gas phase components have been calculated.