Electron density distribution in the ethylene complexes with Pd-containing bimetallic clusters

Abstract

The complexes of PdM bimetallic clusters (M = Cr, Mn, Fe, Co, Ni, Cu, Zn, Ag, Cd) with ethylene are calculated at the density functional theory level with the quantum theory of atoms in molecule approach for the electron density distribution analysis. Formation of the metal–carbon coordination bonds in the studied complexes is determined by the (3, − 1) critical point appearance between the corresponding atoms. The energy of these interactions is estimated as a measure of the PdM clusters adsorptivity. All the C–C, C–Pd and C–M bonds are classified by the characters of the electron density Laplacian at the bond critical point and by the electron energy density. It is shown that the ethylene molecule is strongly activated by adsorption on the PdM clusters. The estimated binding energy between PdM and C₂H₄ is in the range of 58.3–97.8 kcal/mol going from the PdCd(C₂H₄) to the PdNi(C₂H₄) complexes, respectively.

Keywords:

• bimetallic clusters
• density functional theory
• quantum theory of atoms in molecules
• electron density
• electron energy density
• (3, − 1) critical point
• ethylene
• adsorption