in combination with the def2-TZVPP 62 basis set and the auxiliary Coulomb fitting basis set def2/J 63 . All calculations utilized an atom-pairwise dispersion correction with the Becke-Johnson damping scheme . In addition, all calculations were performed for isolated species which were geometry-optimized until an energy convergence criterion of 5 • 10 -6 eH was reached. The presence of a continuous dielectric background ( r = 80.4) with the CPCM method 66 was further considered. All corresponding molecular volumes for the geometryoptimized species were estimated by the GEPOL approach 67,68 . The lists of considered solvents can be found in Tables and. We assumed a temperature of T = 300 K for all calculations.