The discussion above means that the 2SSIPs are predominant whereas the SSIPs are unfavorable in the Zn 2+ //F -solutions prepared by path 2 at the room temperature (300 K). The 2SSIPs↔SSIPs↔CIPs equilibrium has been widely accepted to understand the stepwise ion pairing behaviors . Therefore, intermediate SSIPs are difficult to form, which further blocks the formation of Zn 2+ -F -CIPs in the path 2 solutions. With temperature increasing, the dissociation energy profile shows that energy trough shifts to shorter Zn 2+ -F -distance. For example, at 373 K, the energy trough locates at the range of 3.8-4.5 Å of Zn 2+ -F -distance (Fig. ), suggesting that more outer-sphere complexes exist in the form of Zn 2+ -F -SSIPs in the path 2 solutions at high temperature. This, thus, drives the right shift of ion pair equilibrium reaction to form more CIPs, which is consistent with the NMR experimental observation of Figs. and.