Lewis basicity of alkyl carbonates and other esters. The Gutmann Donor Number (DN), a flawed indicator? Boron trifluoride adduct-formation enthalpy, experimentally or computationally determined, as a reliable alternative

Alkyl carbonates are essential components in the manufacture of lithium-ion batteries, as electrolytes or additives. The Lewis basicity of alkyl carbonates and other carbonyl compounds used in electrochemistry are often characterized by their Donor Number (DN). Assessment of the literature DN values displays great discrepancies. This is attributed in part to experimental errors, but mostly to inconsistent methods of determination. An alternative Lewis basicity scale is proposed, based on the enthalpy of adduct forma-tion of a Lewis base with BF3 in dichloromethane solvent-DH(BF3). Experimental data are well repro-duced by a modified ab initio G4 method and a mixed cluster-continuum approach of solvation. These calculations permit a confident estimation of previously not measured-DH(BF3) values. The combination of a large set of experimental data and of calculations provides a consistent source of Lewis basicity of molecules used in electrochemistry and related fields.(c) 2022 Elsevier B.V. All rights reserved.