Tetravalent metal diphosphonate-phosphite composition in microporous solid crystalline form, with a narrow micropore distribution

US5290746A · kind A · utility

Assignee

• Eniricerche S.p.A. · IT

Inventors

• Giulio Alberti · Perugia, IT
• Umberto Costantino · Perugia, IT
• Riccardo Vivani · Castiglione del Lago, IT
• Piergiorgio Zappelli · Monterotondo, IT
• Antonio Rossodivita · Monterotondo, IT

Key dates

• Filing date: Dec 17, 1991
• Grant date: Mar 1, 1994
• Expiry date: Dec 17, 2011

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07F9/386
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A tetravalent metal diphosphonate-phosphite composition definable by the following general formula: EQU M(O.sub.3 P--R--PO.sub.3).sub.1-x (HPO.sub.3).sub.2x (I) is described where: PA1 M is a tetravalent metal; PA1 x varies from 0.5 to 0.66; PA1 R is an organic radical of bivalent aromatic type, carrying side groups which increase its steric hindrance. The composition is in the form of a crystalline solid with a type .alpha. layered structure with the diphosphonic groups positioned to join said layers together by a covalent bond (pillared compounds). It has a B.E.T. surface area from 300 to 500 m.sup.2 /g depending on the nature of R in formula (I), and a porosity in the micropore radius range of less than 20 .ANG. (Angstrom), such micropores contributing to the extent of more than 95% of the total area for the most crystalline materials.