The kinetics of the following reductive elimination of biphenyls from Pt(II) diphosphine complexes was investigated. The table below shows some of the results: Ar Ar Ph Pt PdLn Ph- -Ph d-toluene, 100C Ph Ar Ar k(s) 1.8 x 107 Ast (cal/mol K) AH* (kcal/mol) Ar Group Ph 7.8 11.5 4.7 x 107 4-F-C6H4 37.2 11.8 3.6 x 106 2,6-F2-C6H3 31.7 1.1 2,4,6-F3-C6H2 C6F5 6.9 x 106 30.9 0.1 2.2 x 104 28.7 1.4 Explain what the results listed in the table indicate about the mechanism of the reaction. What is the nature of the transition state in the rate-determining step?