In the field of hydride transfer reactions, overcoming the slowness of the transfer is an important challenge. In this study, we investigated the reaction mechanism of the transfer from a (2,2¤:6¤,2¤¤-terpyridine)(2,2¤-bipyridine)ruthenium(II) hydrido complex to a NAD(P)+ model compound, 3-carbamoyl-1- methylpyridinium by means of density functional theory. One of the calculated transition states is in good agreement with our kinetics observations (activation Gibbs energy, activation volume by means of high pressure apparatus, and kinetic isotope effect) about the transition state in the rate-determining step, indicating that the carbamoyl group (especially carbonyl group) in the NAD(P)+ model helps to complete the transfer by modulating the kinetic hydricity on an ad hoc basis. [ABSTRACT FROM AUTHOR]