The structures, stabilities, nature of bonding, and spectroscopic properties of the new actinide imine molecules, neptunimine (HN=NpH2) and plutonimine (HN=PuH2), in the gas phase have been systematically explored at different levels of theory. Our calculation indicates that HN=AnH2 (An=Np, Pu) should be nonplanar and have a quartet ([Formula: see text]) and quintet ([Formula: see text]) ground state, respectively. The nature of the chemical bonding in these molecules were investigated by employing topological methods including electron localization function (ELF), atoms in molecules (AIM) as well as natural bond orbital analysis (NBO). The results showed that these actinide complexes possess relatively strong An=N multiple bonds between the An 6d-5f hybrid orbitals with N 2s-2p orbitals. The charge decomposition analysis (CDA) diagram demonstrated that the transition of electrons mainly happened inside the AnH2 of HN=AnH2. Total and partial density of state (TDOS and PDOS) and also overlap population density of state (OPDOS) diagrams analysis were implemented. The IR and Raman spectra were theoretically simulated as a convenient way to confirm the existence of the actinide imine complexes in further experiments.
Keywords: IR and Raman spectra; Multiple bonds; Neptunimine; Plutonimine; Structures; Topological analysis.