MESOPOROUS CRYSTALLINE SOLID COMPOUND OF A DIPHOSPHONATE/PHOSPHITE OF A TETRAVALENT METAL, WITH A NARROW DISTRIBUTION OF MESOPORES

摘要

The present invention discloses a compound comprising a diphosphonate/phosphite of a tetravalent metal: M[(O3P-R-PO3)1-(x+y) (HPO3)2X(O3P-R-PO3H2)2y] (where M, R, x and y have the meaning given in the description), in the form of a crystalline solid with an alpha-type lamellar structure with a distance between layers of 7.4 to 20 ANGSTROM (depending on the dimensions of radical R), a BET surface area of 250 to 400m2/g, and porosity within the mesopore range, with at least 50% of the pores measuring 20 to 30 ANGSTROM . The compound, depending on the radical R used, may or may not have microporosity in the region between layers. Such a diphosphonate/phosphite of a tetravalent metal is obtained by reaction between diphosphonic acid, phosphorous acid and an oxyhalide of a tetravalent metal, in a solvent comprising dimethyl-sulphoxide/water containing hydrofluoric acid.