NOVEL Crystal
Structures of Vanadyl Gallophosphates
Department of Chemistry, National Tsing Hua
University, Hsinchu, Taiwan 300 (slwang@mx.nthu.edu.tw)
Substitution of the first-raw transition metal (TM) ions for Al3+
in the frameworks of aluminum phosphates is of particular interest for the
enhancement of catalytic activity and the design of novel catalysts. The
location and environment of the TM ion site is of considerable importance for
understanding the catalytic and adsorptive properties of molecular sieves. As
only few single-crystal data available for most of the MAlPO-n samples, actual incorporation of TM ions into the tetrahedral
frameworks is difficult to prove [1] Owing to the similarity in the
framework topology, the search for gallium phosphates adopting microporous
structures has attracted much attention [2,3] By employing hydrothermal
crystallization, we have prepared a series of novel open frameworks including
the first 24-ring containing gallium phosphate phase [4] which exhibits large
channels with a measured pore diameter of ~11.2 . In this presentation, the
crystal structures and magnetic properties of several large-channel containing
VGaPO frameworks shall be described and discussed.
References
1
Hartmann, M., Kevan, L., (1999) Chem. Rev. 99, 635, and references therein.
2
Cheetham, A. K., Ferey, G., Loiseau, T. (1999) Angew. Chem. Int. Ed. 38, 3268.
3
Lin, C. H., Wang, S.
L. (2000) Chem. Mater. 12, 3617, and references therein.
4
Lin, C. H., Wang, S. L., Lii,
K. H. (2001) J. Amer. Chem. Soc. 123, 4649.