“…31,32 The noteworthy results were found when X = OH was incorporated, displaying excellent activity of 2.4 × 10 6 with high polymer molecular weights and narrow dispersity at 100 °C. 34 On the other hand, complexes with fluorinated-benzhydryl steric substituents displayed superior catalytic performance, particularly in thermal stability ( VI , Fig. 1): X = F, activity 0.24 × 10 6 at 80 °C; X = NO 2 , activity 6.01 × 10 6 at 80 °C; X = OMe, activity 4.82 × 10 6 at 50 °C; X = Me, activity 7.08 × 10 6 at 80 °C; X = t Bu, activity 4.34 × 10 6 at 90 °C.…”