Mossbauer spectroscopy studies were developed in order to obtain an evaluation of different physicochemical factors characterizing the electronic structure of the local sites (CuO6) into three copper(III) oxides: LaCuO3 having a three-dimensional (3D) perovskite structure; SrLaCuO4 and La2Li0.50Cu0.50O4 witha two-dimensional (2D) K2NiF4-type structure. All these matrixes have been doped with Fe-57 (1 at.%) Mossbauer probe atoms. Such evaluation was based on analysis of the Fe-57 Mossbauer parameters (isomer shift and quadrupole splitting) characterizing the formal oxidation state and the local structure of the The obtained results underline that four main factors play an important role in the Fe-57 robe atoms. The obtained results underline that four main factors play an important role in the stabilization of formally trivalent "Cu3+" ions: (i)the involved preparation process (in particular the oxygen pressure level able to impede the formation of oxygen vacancies); (ii) the dimensionality (3D or 2D) of the lattice; (iii) the chemical surrounding and (iv) the local structural distortion of the transition metal site (CuO6), both last factors governing the local crystal field energy, orbital ordering and a possible charge transfer Cu3+-O2- <-> Cu2+-O-(L). (C) 2008 Elsevier B.V. All rights reserved.