Synthesis and spectroscopic characterization of the new perfluoro-compound CF3CF2C(O)NCS

YANINA BERRUETA MARTINEZ; LUIS RAMOS; CARLOS O. DELLA VÉDOVA

Schmitten

Congreso; 15. Deutscher Fluortag; 2012

deutschen Fluorchemiker

The thermolysis of fluoropolymers and the degradation of fluorotelomer alcohols (FTOHs, linear fluorinated alcohols with the formula CF3(CF2)nCH2CH2OH, n=1,3,5,...) results in the emission of perlfuorocarboxylic acids to the atmosphere [1]. Perfluoropropionic acid, CF3CF2C(O)OH, is a short chain perfluorocarboxylic acid with a significant vapour pressure, which serves as a representative model for comparison to environmentally important perfluorinated carboxylic acids. It was studied and used as a intermediate for the preparation of two perfluoropropionyl derivatives: The CF3CF2C(O)NCS was isolated and characterized with different techniques: UV-Vis, FT-IR, Raman, NMR 13C, NRM 19F, and mass spectrometry. The calculations show the coexistence of four conformers in equilibrium at room temperature: syn-syn (16.7%), syn-anti (16.5%), gauche-syn (33.4%) and gauche-anti (33.3%). Small energy barriers for the interconversion gauche-anti → gauche-syn (0.43 kcal / mol) and syn-anti → syn-syn (0.66 kcal / mol) were found. [1] N. Rontu, V. Vaida, J. Mol. Spectrosc. 237 (2006) 19-26.