Compared to the c 4 structures, the c 3 linkers are bulkier and thus cause a greater increase in the energy of the complex as they approach the Cp * ring or each other. The Rh(I) species is particularly susceptible to this, as illustrated in Figure . For small bite angles, the ligands' P-H bonds are forced directly toward each other in the Rh(I) species, while the acetonitrile or hydrogen of Rh(III)A and Rh(III)H redirects the bonds to point away from each other. Similarly, for large bite angles, the linker groups of the Rh(I) species encroach on the Cp * ring, while for Rh(III)A and Rh(III)H the linkers are arranged closer to parallel with the Cp * , reducing the steric strain. This is why Reactions 1 and 3 have such different bite angle trends for P(c 3 ) than in the P(c 4 ) scan, as the steric strain of the P(c 3 ) Rh(I) compound is significantly greater for the smallest and largest bite angles.