Insight into the Construction of Open-framework Aluminophosphates

Inorganic open-framework materials with regular pore architectures have widespread applications in the fields of catalysis, adsorption, separation, host-guest assembly and advanced functional materials. Since the discovery of aluminophosphate molecular sieves AlPO4-n in the early 1980s by Union Carbide, there has been enormous growth in the structural and compositional diversity in open-framework metal phosphates. Apart from traditional aluminosilicate zeolites, open-framework aluminophosphates (hereafter denoted AlPOs) constitute the most important class of microporous materials with a variety of structures ranging from neutral zeolite frameworks to anionic frameworks with 3-D interrupted frameworks and low-dimensional networks. The discovery of open-framework AlPOs has brought some conceptual breakthrough for traditional microporous compounds, i.e., the framework elements not only limited to Al and Si atoms, the upper-limit of pore size not only delimited to 12-MR, and the primary building units not only defined to tetrahedra, etc, particularly the recent development of diverse low-dimensional structures provides some mechanism clues on the formation of open-framework materials. Furthermore, the on-going search for new structures also improves the current application areas of microporous materials.

Recently, we have built up a structure database containing over 200 AlPO structures reported in the literature. This database is designed for structural data of all 3-dimensional microporous aluminophosphates and their lower dimensional derivates. Besides some general information, such as formula, space group, cell parameters, and atomic coordinates, etc., this database also includes more detailed structural information, such as coordination environment, Al/P ratio, stacking sequences for 2d structures, and coordination sequences. Simulated XRD reflections and references are also included to aid the identification of users' samples.

Last updated: JUN 6th, 2007

References:

1. Wilson, S. T.; Lok, B. M.; Messian, C. A.; Cannan, T. R.; Flanigen, E. M. Aluminophosphate molecular sieves- a new class of microporous crystalline inorganic solids, J. Am. Chem. Soc. 1982, 104, 1146-1147.

2. Bennett, J. M.; Dytrych, W. J.; Pluth, J. J.; Richardson, J. W. Jr.; Smith, J. V. Structural features of aluminophosphate materials with Al/P = 1, Zeolites, 1986, 6, 349-361.

3. Baerlocher, Ch.; McCusker, L. B. Database of Zeolite Structures: http://www.iza-structures.org/databases/.

4. Yu, J. H. and Xu, R. R. Rich structure chemistry in the aluminophosphate family, Accounts of Chemical Research, 2003, 36(7): 481-490.

5. Yu, J. H. and Xu, R. R. Insight into the construction of open-framework aluminophosphates, Chem. Soc. Rev., 2006, 35, 593-604