The Syntheses of Hydrotalcite-Like Compounds and Their Structures and Physico-Chemical Properties I: The Systems Mg2+-Al3+-NO3, Mg2+-Al3+-Cl, Mg2+-Al3+-ClO4, Ni2+-Al3+-Cl and Zn2+-Al3+-Cl

Shigeo Miyata
Kyowa Chemical Industry Co. Ltd., Yashimanishi-machi, Takamatsu-shi, Japan

Abstract: The basic salts of this system were prepared and their structures and physico-chemical properties were studies by electron microscopy, chemical analysis, X-ray powder diffraction, thermal analysis, i.r. absorption spectra, BET absorption, and acidity-basicity measurements. The salts were found to be new compounds analogous to hydrotalcite. They can be expressed by the formula; [Mx2+ My3+(OH)2(x + y)]y+ [Az1Az22−·mH2O]−(z1+2z2) where M2+ and M3+ denote di- and trivalent cations, A and A2− denote mono- and divalent anions, respectively, and y = z1 + 2z2 ; z1z2.

The structures consist of positively charged Cd(OH)2-1ike basic layers and intermediate layers formed from anions and water molecules with the solid solution of divalent cation (M2+) and trivalent cation (M3+) being formed in the range of 0.6<x/(x + y) < 0.9. The anions of Cl, NO3 and ClO4 are easily substituted by CO32−. A large part of the NO3 makes a monodentate-type bond and the ClO4 a bridge-type bond.

Clays and Clay Minerals; November 1975 v. 23; no. 5; p. 369-375; DOI: 10.1346/CCMN.1975.0230508
© 1975, The Clay Minerals Society
Clay Minerals Society (www.clays.org)