  Optical pumping of molecules provides unique opportunities for the control of
chemical reactions at a wide range of rotational energies. Chemical reactivity
for the hydrogen abstraction reaction SiO$^+$ + H$_2$ $\rightarrow$ SiOH$^+$ +
H is investigated in an ion trap. The SiO$^+$ cation is prepared with a narrow
rotational state distribution, including super-rotor states with rotational
quantum number $\it{(j)}$ as high as 170 using a broad-band optical pumping
method. The super-rotor states of SiO$^+$ are shown to substantially enhance
the reaction rate, a trend reproduced by complementary theoretical studies. The
mechanism for the rotational enhancement of the reactivity is revealed to be a
strong coupling of the SiO$^+$ rotational mode with the reaction coordinate at
the transition state on the dominant dynamical pathway. This work reports for
the first time a chemical reaction with extreme rotational excitation of a
reactant and its kinetic characterization.
