ISSN:
1573-4854
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract After a brief illustration of the structures of three-layered zirconium phosphates, some general concepts on the influence of the structural characteristics on the distribution of the pillars, as well as some general strategies used to obtain microporous pillared compounds, are discussed. The synthesis of covalently pillared α-zirconium phosphite diphosphonates is first described and the use of pillars with bases for the creation of microporosity in the interlayer region is reported. The structure of a microporous compound in which the pillar with bases 3,3',5,5'-tetramethyl-biphenyldiphosphonate was used (interlayer microporosity 405 m2 g-2, micropore volume 0.16 cm3 g-2, pore size 0.5 nm), is described. The controversial results reported in the literature for microporous compounds of α-zirconium phosphate pillared with inorganic polyoxycations are also discussed. Particular emphasisis is then given to recent results on the preparation of microporous compounds by topotactic pillaring of γ-zirconium phosphate with organic radicals. The preparation and structure of the compound pillared with ≈25% of biphenyldiphosphonate groups is illustrated. A large specific surface area (≈320 m2 g-2), a great micropore volume (0.12 cm3 g-2) and a narrow micropore distribution with an average diameter of 0.58 nm, was obtained. The topotactic pillaring of γ-zirconium phosphate with nonrigid pillars and with crown ethers, as well as the encouraging prospects for the preparation of microporous and thermally stable compounds from γ-ZrP pillared with polyoxycations, are then examined. Finally, the possibility of preparing microporous solids by pillaring the recently discovered ZrPO4Cl(dmso) with dicarboxilates, is reported.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1009678120336
Permalink
