The NBO analysis, as depicted in Figures .3 and S3.4, reveals that the highest values correspond to the presence of charge transfer interactions specifically associated with hydrogen bond formation for both cases, for charged and neutral systems, respectively. These interactions involve the donation of electron density from the lone pair (LP(X -)) of the anion to any sigma antibonding orbital involving the theoretically positively charged nitrogen atom (BD * (N)). The obtained values of E(2), which represent the stabilisation energy due to charge transfer between the aforementioned orbitals, follow a trend similar to that of the interaction energy with respect to different substituents, i.e. CF 3 > CH 3 > t Bu. Furthermore, considering the charged systems, we find that the E(2) values are higher than their neutral counterparts because of the positive charge distribution within the molecule. Nevertheless, the nature of the charge transfer interaction remains un-