LAUSR

Abstract Transition metal hydride (TMH) plays a critical role in the field of chemical catalysis and catalytic transformations. Knowledge of enthalpies for cleaving metal hydride bonds enables the prediction of chemical reactivity, such as for the bond-forming and bond breaking events that occur in a catalytic reaction especially in the hydrogenation of carbon dioxide. Thermochemistry of the first row TMHs, MH+/0/− (M = Sc−Zn) were calculated at both the Density Functional Theory (DFT) level and the CCSD(T) level. Thermochemistry hydricity is the energy required to cleave an M–H bond to generate a hydride ion (H−). The heterolytic bond cleavage with proton dissociation is the acidity of the metal hydride. The homolytic bond-dissociation energy (BDE), involves formation H . Periodic trends of H−, H+, H donor ability are discussed and compared among the different elements and every MH+/0/− systems. Note that, we can find suitable methods and avoid bad methods for different element. The study could give certain theoretical guidance on the catalysis of TMH.