Microporous montmorillonites expanded with alumina clusters and M[mu-OH)Cu(mu-OCH2CH2NEt2)](6)(ClO4)(3), (M = Al, Ga, and Fe), or Cr[(mu-OCH3)(mu-OCH2CH2NEt2)CUCl](3) complexes

Expanded clays bipillared with [Al13O4(OH)(24)(H2O)(12)](7+) ions and with hexameric Cu complexes such as M[(mu-OH)Cu(mu-OCH2CH2NEt2)](6)(ClO4)(3), or with M[(mu-OH)Cu(mu-OCH2CH2NEt2)](6)(PF6)(3) where M = Fe, Al, Ga, form mi croporous materials whose stability and microporosity depend mainly on the identity of the hexamer central metal atom. In fact, a general decrease in thermal stability, interlamellar heights, surface areas, and pore volumes w as noted when, in the (Cu,M) hexamer, M changed from gallium to aluminum to iron. Mossbauer results have indicated that only Fe3+ in octahedral coordi nation is present in the iron-containing bi-PILC samples (bi-PILC = bipilla red interlayered clays). It is believed that metals such as Fe3+ and Cu2+ c an interact with the interlamellar Keggin ions thereby decreasing the stabi lity of the alumina pillars. In contrast, the intermediate Al-13-PILC struc ture is least affected when the more stable Cr complex is used. Bi-PILC mat erials containing 2.7-3.4% Cr stable to 500 degrees C have been obtained. T he low polarity of the chosen solvent (acetonitrile) appears to inhibit the back-exchange of the intermediate PILC's Keggin ions with the hexameric Cu complexes. Elemental analysis together with XRD results suggests that the primary intercalation pathway was diffusion or ion exchange when Cr[(mu-OCH 3)(mu-OCH2CH2NEt2)CuCl](3) or M[(mu-OH)Cu(mu-OCH2CH2NEt2)](6)(ClO4)(3), res pectively, was used. In all preparations, bi-PILC were produced containing complexes that suffered ligand losses during the synthesis reaction. Molecu lar scale AFM images have shown that these complexes can be found also outs ide the clay interlamellar space.