Theoretical Study Of Electronic Structures Of Several Representative Metal Element In The Hydrotalcite Slabs

A series of complexes and slab unit of hydrotalcites, which include several representative metal elements Mg²⁺, Mn²⁺, Al³⁺, Cr³⁺ and ligands H₂O/OH^-, have been studied using density functional theory(DFT). In addition, the reaction mechanism of double bond isomerization of butene catalyzed by HF has been investigated. The main results are as following:(1) Theoretical study on electronic structures of [Al(OH)_m(H₂O)_n]^x complexes The calculations of the complexes at the B3LYP/6-311+G(d,p) level show:for the complexes containing the same kind of ligands, the more the ligands of Al³⁺ are, the longer the bond length of Al-O is correspondingly; for the complexes including the same number of ligand, the bond length of Al-O of [Al(H₂O)_m]^x are longer than that of [Al(OH)_m]^x; the NMR calculations show that the NMR chemical shift value of the four, five and six coordination Al³⁺ complexes are close to the experimental values.(2) Theoretical study on electronic structures of several representative complexes composed of metal element Mg²⁺, Mn²⁺, Cr³⁺ and ligand H₂O/OH^-It is found that six-coordination complexes Mg(H₂O)₆²⁺, Cr(H₂O)₆³⁺, Cr(OH)₆^3-, Mn(H₂O)₆²⁺ and Mn(OH)₆^4- are octahedronal; Mg(H₂O)₄²⁺ are all tetrahedronal; Cr(OH)₄^-, Mn(OH)₄^2- and Mn(H₂O)₄²⁺ are almost configuration of plane square; Cr(H₂O)₄³⁺ is anamorphic tetrahedronal; it can be shown that the HOMO energy of the complex Mn(OH)₆^4-, Cr(OH)₆^3- are the highest among all the HOMO energies of species respectively, and their energy...