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

The adsorption capability of ?-diimines N-ethylamine-1,2-dimethyl-?-diimine, N-ethylhydroxy-1,2-dimethyl-?-diimine and N-ethylthiol-1,2-dimethyl-?-diimine over iron-clusters was studied by DFT. The results show that since these compounds possess suitable structural and electronic parameters for metal adhesion, ?-diimines strongly adsorb over the metal clusters. Moreover, the calculated binding energy supports the existence of a bond between ?-diimine and the iron metal, consisting of the transfer of high-charge density which in the delocalization region (N1double bond; length as m-dashC2C3double bond; length as m-dashN4) is formed by p (nitrogen) and ? (Cdouble bond; length as m-dashN) to the metal (L(?) ? 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).