To observe how the ∆∆E R Y changes as a function of the bite angle, we first assess the P(c 4 ) structures, as these models most closely represent the full phosphorus linker complexes discussed in the previous sections. Each reaction depends linearly on the bite angle until 90 • , after which ∆∆E R Y changes more slowly. ∆∆E R1 P(c 4 ) is very flat, increasing by just 1.5 kcal/mol over the whole scan, which suggests hydrogen addition is largely unaffected by the coordination environment around the rhodium. ∆∆E R2 P(c 4 ) (hydrogen → acetonitrile exchange) increases linearly with bite angle, by a total of 7.5 kcal/mol over the whole range. Consistent with the fact that the overall ∆∆E R Y for the cycle must be zero, see Eq. 4, ∆∆E R3 P(c 4 ) (release of acetonitrile) decreases linearly over the course of the scan. The acetonitrile molecule seems to be sterically hindered from binding as the bite angle widens, making Rh(III)A the less favorable species for Reactions 2 and 3. The Rh and P(c 4 ) charges, reported in Figures and in the SI, respectively, also support the notion that the bite angle dependence of the reactivity stems from steric bulk. For each reaction, the charges of rhodium and the linker P(c 4 ) atoms remain almost entirely flat with respect to bite angle, leaving steric effects as the likely cause of the change in reactivity for Reactions 2 and 3.