DFT studies of α-diimines adsorption over Fen surface (n = 1, 4, 9 and 14) as a model for metal surface coating

The adsorption capability of α-diimines N-ethylamine-1,2-dimethyl-α-diimine, N-ethylhydroxy-1,2-dimethyl-α-diimine and N-ethylthiol-1,2-dimethyl-α-diimine over iron-clusters was studied by DFT. The results show that since these compounds possess suitable structural and electronic parameters for metal adhesion, α-diimines strongly adsorb over the metal clusters. Moreover, the calculated binding energy supports the existence of a bond between α-diimine and the iron metal, consisting of the transfer of high-charge density which in the delocalization region (N1C2–C3N4) is formed by p (nitrogen) and π (CN) to the metal (L(σ) → Fe). Furthermore, the binding nature of the compounds with the metal is then confirmed in molecular orbital studies by detecting the overlap of HOMO (diimines) with LUMO (iron).