ARTICLE DOI: 10.1002/zaac.201100404 Isolation and Characterization of CH 3 OC(O)OOC(O)F from the Reaction CH 3 OH + FC(O)OOC(O)F Matias Berasategui, [a] Maximiliano A. Burgos Paci, [a] and Gustavo A. Argüello* [a] Dedicated to Professor Helge Willner on the Occasion of His 65th Birthday Keywords: New peroxide; FTIR spectroscopy; Density functional calculations; Reaction mechanisms; Synthesis Abstract. The synthesis of CH 3 OC(O)OOC(O)F is accomplished by the thermal reaction between CH 3 OH and FC(O)OOC(O)F at room temperature. The new peroxide is obtained in pure form after repeated trap-to-trap condensation and it is characterized by NMR and IR spec- troscopy and mass spectrometry. Geometrical parameters were studied by ab initio methods [B3LYP/6-31++G(d,p)]. CH 3 OC(O)OOC(O)F is stable for a few hours at room temperature, and it decomposes into CO 2 , CO, HF, HC(O)OH, and CH 2 O. Introduction Since the replacement of chlorofluorocarbons (CFCs) by compounds commonly designated as hydrofluorocarbons (HFCs), there have been exhaustive studies on the mechanism of HFCs degradation reactions. [1–6] Along with these, much work has been devoted in the past decade to the study of many compounds and radicals containing only fluorine, carbon, and oxygen atoms that can be formed in the laboratory as a result of the degradation of HFCs in the presence of oxygen and of high concentrations of CO. The study of these reactions af- forded the novel synthesis of many new compounds, generi- cally called fluorocarbooxygenated molecules. Several of such compounds, however, had been known for many years, par- ticularly FC(O)OOC(O)F, which besides having being synthe- sized by various methods, [7–9] had been used as a polymeriza- tion initiator. [10] Further research on this peroxide over four decades involved elucidating its IR spectrum, [11,12] studying its gas-phase structure, [13] chemistry, [14] and potential as a reagent for synthesis, [15,16] carrying out a theoretical density functional study [17] and studying its role in atmospheric chemistry as a precursor of FCO 2 radicals. [18,19] Methanol is a trace component of our atmosphere, with con- centrations measured in the upper troposphere [20,21] ranging between 400–800 ppt. However, according to its global pro- * Prof. Dr. G. A. Argüello Fax: ++011-351-4334180 E-Mail: gaac@fcq.unc.edu.ar [a] INFIQC, Departamento de Físico Química Facultad de Ciencias Químicas Universidad Nacional de Córdoba Ciudad Universitaria 5000 Córdoba, Argentina Z. Anorg. Allg. Chem. 2012, 638, (3-4), 547–552 © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 547 The boiling point is extrapolated to 366.5 K from the vapor pressure curve log p= 8.623–2061/T (p /mbar, T /K). The mechanisms for both the formation and thermal decomposition of CH 3 OC(O)OOC(O)F are discussed, and some physicochemical properties are compared with those of related compounds. duction, the sources largely exceed its known sinks. [20] This mismatch indicates that substantial and still unknown removal processes different from OH removal must exist. Though FC(O)OOC(O)F is not an atmospheric constituent itself, it reacts with CH 3 OH under laboratory conditions yield- ing a new molecule that has been isolated and characterized for the first time, namely methyl fluoroformyl peroxycarbon- ate, FC(O)OOC(O)OCH 3 . Such molecule is of interest since it couples a fluorinated and a hydrogenated radical together, whose combined properties could therefore represent a transi- tion from a purely fluorocarbooxygenated molecule to a hydro- genated one. The present contribution has a manifold purpose, namely reporting on the first synthesis of FC(O)OOC(O)OCH 3 charac- terized by spectroscopic techniques, presenting DFT calcula- tions of the structure and reaction path for its formation, and proposing a mechanism for its decomposition. Some observa- tions are also made on the title reaction in a highly fluorinated environment. Results and Discussion The new compound is a colorless liquid, stable for a few hours at room temperature in a stainless steel container, but decomposing faster in the presence of glass surfaces. The de- composition products were surface-dependent. In stainless steel, CO 2 , CO, HF, CH 2 O, and HC(O)OH were identified by FTIR, while in glass the formation of SiF 4 , CO 2 , CO, and a polymer, among other products, was observed. The vapor pressure of CH 3 OC(O)OOC(O)F within the 233– 273 K temperature range follows the equation log p = 8.623–