The interaction of 1,3-diethers and MgCl2 support was studied. It was found 1,3-diethers interact with the surface of MgCl2 support more selectively than esters. 1,3-Diethers form several surface complexes of different strength. At that, a strength of all surface complexes of 1,3-diethers considerably exceeds a strength of surface complexes of ethyl benzoate. The strength of some surface complexes of 1,3-diethers is close to that of surface complexes of dibutyl phthalate, and dibutyl phthalate is able to substitute 1,3-diethers from these complexes. The least strong surface complexes of 1,3-diethers are labile and can also be removed from the MgCl2 surface without action of any electron donors. In contrast to the MgCl2 support, the catalyst contains only more strong and unremovable surface complexes of 1,3-diether. This testifies on the formation of certain faces of MgCl2 during catalyst preparation in the presence of 1,3-diether contrary to the formation of different MgCl2 faces at the preparation of the MgCl2 support. (C) 2012 Elsevier B.V. All rights reserved.