The Affinity of Some Lewis Bases for Hexafluoroisopropanol as a Reference Lewis Acid: An ITC/DFT Study. Issue 18 (17th August 2020)

• Record Type: Journal Article
• Authors: Milovanović, Milan R.; Dherbassy, Quentin; Wencel‐Delord, Joanna; Colobert, Françoise; Zarić, Snežana D.; Djukic, Jean‐Pierre
• Is Part Of: Chemphyschem. Volume 21:Issue 18(2020)
• Page Start: 2136
• Page End: 2142
• Publication Date: 2020-08-17
• Subjects: density functional theory -- hexafluoroisopropanol -- isothemal titration calorimetry -- Lewis adducts -- solvation; Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.202000560
• Languages: English
• ISSNs: 1439-4235

Abstract

Abstract: To figure out the possible role of 1, 1, 1, 3, 3, 3‐hexafluoropropan‐2‐ol (HFIP) as well as to provide reference thermochemical data in solution, the formation of Lewis acid‐base complexes between HFIP (Lewis acid) and a series of 8 different Lewis bases (3 sulfoxides, 3 Nsp 2 pyridine derivatives, 1 aromatic amine, 1 cyclic aliphatic ether) was examined by isothermal titration calorimetry (ITC) experiments and static density functional theory augmented with Dispersion (DFT−D) calculations. Measured ITC association enthalpy values (Δ H a ) lie between −9.3 and −14 kcal mol −1 . Computations including a PCM implicit solvation model produced similar exothermicity of association of all studied systems compared to the ITC data with Δ H a values ranging from −8.5 to −12.7 kcal mol −1 . An additional set of calculations combining implicit and explicit solvation by chlorobenzene of the reactants, pointed out the relatively low interference of the solvent with the HFIP‐base complexation: its main effect is to slightly enhance the Gibbs energy of the HFIP‐Lewis base association. It is speculated that the interactions of bulk HFIP with Lewis bases therefore may significantly intervene in catalytic processes not only via the dynamic microstructuring of the medium but also more explicitly by affecting bonds' polarization at the Lewis bases. Abstract : Affecting Lewis bases : The formation of Lewis acid‐base complexes between HFIP (Lewis acid) and a series of different Lewis bases (sulfoxides, amines, dioxane) was examined by isothermal titration calorimetry (ITC) experiments and static density functional theory augmented with dispersion (DFT−D) calculations.