The role of carbones (CL2; L = phosphines vs carbenes) as Lewis bases in dihydrogen (H-2) activation reactions in the presence of the Lewis acid B(C6F5)(3) has been computationally explored by means of density functional theory calculations. To this end, the interaction between H-2 and the [carbone center dot center dot center dot B(C6F5)(3)] pair along the reaction coordinate has been quantitatively analyzed in detail and compared to the parent ['Bu3P center dot center dot center dot B(C6F5)(3)] frustrated Lewis pair. In addition, the influence on the reactivity of both the nature of the central E atom and the surrounding ligands in ylidones (EL2) has also been considered. It is found that the activation barrier of the H-2 activation reaction as well as the geometry of the corresponding transition states strongly depends on the nature of both E and L in the sense that lower barriers are systematically associated with earlier transition states. Our calculations identify heavier EL2 as the most active systems to achieve facile H-2 activation reactions.