CEQUINOR   05415
CENTRO DE QUIMICA INORGANICA "DR. PEDRO J. AYMONINO"
Unidad Ejecutora - UE
artículos
Título:
- Structural study of the complex of Al (III) with 1,2-benzenediol. Solvent effects
Autor/es:
M. I. SANCHO; A.H.JUBERT; S. E. BLANCO; , F. H. FERRETTI; E.A.CASTRO
Revista:
Global Journal of Molecular Sciences
Editorial:
IDOSI Publications
Referencias:
Año: 2006 vol. 1 p. 1 - 41
ISSN:
1990-9241
Resumen:
The stability of the complex formed by two molecules
of 1,2-dihydrobenzene and one molecule of AlCl3 in solution with different
permitivity and temperatures was investigated by means of the B3LYP/6-31G(d)
method and using the IPCM model. It was assumed that the formation of the
complex takes place by simple reactions between ions of opposite charges. It
was also proposed an equation that explains the changes of the complexation
equilibrium constant with the permitivity of the reaction medium. The
calculations performed allowed to prove that the increase of the hydrogen-bon
donor ability of the solvents favor a higher thermodynamic stability of the
reactants with respect to the complex and therefore a decrease of the
corresponding equilibrium constants. The non-phase structure proposed for the
complex is coherent with the small batochromic shift experimentally observed.
In the complex molecule the planes containing the phenyl rings are inclined by
9,2 withrespect to the plane that includes the aluminium nd oxygen atoms. It
was concluded that the formation of the complex is an endothermic process which
involves covalent bonds between metal atom and oxygen atoms of catechol and
stronger coulombic attractions between the referred atoms and water molecules.