Porous solids and catalysts

The synthesis of the Al2[03PC2H4P03](H20)2F2 H20 (7) was performed by mixing Al2(S04)3-18H20 (Aldrich), ethylenediphosphonic acid (Lancaster), HF/ pyridine (70 wt % HF, Aldrich), pyridine (Aldrich), and de-ionised water in the molar ratio 1 2.16 8.7 54 144. The reaction mixture (initial pH = 6) was sealed in a Teflon-lined steel autoclave and heated under autogenous conditions at 170 °C for 5 days. Al2[03PC3H6P03](H20)2F2 H20 II) was synthesized using a similar synthesis procedure. The obtained crystalline products were separated by suction filtration, washed in distilled water and acetone, and dried in air. 

5 mm diameter Lindemann glass capillary of sample I was mounted on the powder diffractometer at station 2.3 at CCLRC Daresbury Laboratory, Synchrotron Radiation Source and room temperature synchrotron X-ray data were collected. The mean wavelength used was 1.2999 A and data were collected from 6 to 80° 20. The diffractometer operated with a Si(lll) monochromator, parallel foils prior to the detector and a scintillation detector. The sample was spun during data collection to minimise preferred orientation and sampling effects. Data were collected on sample II in a similar manner but at a wavelength of 1.3000 A. 

A preliminary study of the energetics of this system has been performed to understand the driving forces that give rise to the structures adopted by both / and 7/in 

The total energy calculations on both the ethyl- and propyl-containing systems indicated that the hypothetical structures (///and IV) were between 115 and 85 kJ mof less stable than the experimentally observed structures (/and II, respectively). 

The unit cells of structures / - IV were deconstructed in order to determine the 

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