High-pressure-limit rate coefficients for the association reactions were obtained using a rigorous direct dynamics approach within the variable-reaction-coordinate transition-state theory (VRC-TST) formalism. Thermochemistry was calculated using composite schemes, laddered to reduce uncertainties, and collisional energy transfer parameters were evaluated both by direct dynamics and by analogy to similar systems. Then, a master equation (ME) approach was used to obtain the reverse dissociation rate constants and examine the falloff behavior.