Dihydrogen Activation: To explore the energetic feasibility of the postulated dihydrogen activation process, we performed DFT calculations using the M06L functional and a hybrid basis set (see supporting information for details). In the solid state, 1 possesses an arrangement in which the core of the β-diketiminate ligand, the Zn-N motif, and the phenyl ring of the anilide all lie within the same plane (Figure ). This conformation is reproduced by DFT calculations and results in an electronic structure in which the frontier molecular orbitals of 1 are perfectly set up to react with dihydrogen. Hence, the natural localized molecular orbitals (NLMOs) of 1 allow the visualization of the 2p-orbital on N and the 4s-orbital on Zn, which contribute to the HOMO and LUMO+1, respectively (Figure ). The dual Lewis acidic / Lewis basic behavior of the Zn-N bond of 1 was further supported by attempts to prepare an analogue of this compound. Variation of the steric demands of the ligand on zinc (Ar = 2,6-diisopropylphenyl vs 2,6-diethylphenyl) led to the isolation of the zincate complex 4, in which an equiv. of Li-Cl is coordinated to the Zn-N bond (Figure ). Dihydrogen activation by 1 was calculated to occur through a stepwise process involving the formation of a weakly bound encounter complex Int-1 which leads to TS-1. Int-1 is an unstable encounter complex of zinc with dihydrogen. While there is a component of bonding that involves donation of electron density from the H-H bond to the vacant 4s-orbital of Zn in Int-1, it is not significant enough to assign this as a Hydrozincation: Direct hydrozincation of unsaturated bonds is well known, with the majority of reports focusing on polar substrates. However, the direct hydrozincation of alkynes has received little attention. Ingleson and coworkers reported that a cationic two-coordinate zinc hydride species was capable of adding across the triple bond of various alkyne substrates. They also went on to develop a catalytic system for di-and triborylation of terminal alkynes, and showed that their cationic, twocoordinate complex outperformed complex 2 in this system. Direct hydrozincation was also proposed to occur in the zinc-catalysed hydroboration of alkynes reported by Geetharani and coworkers. These reports cover reactivity with terminal and internal alkynes, however, methods for the uncatalyzed hydrozincation of alkenes is rare.