Department of Chemistry, National Central
University, Chungli, Taiwan 320, R.O.C. (liikh@cc.ncu.edu.tw)
Organically templated metal phosphates have been extensively studied
because of interesting structural chemistry and potential applications in
catalysis. However, in most cases the organic templates cannot be removed
without collapse of the frameworks. This is in contrast to the high thermal
stability and extensive applications of zeolites in refinery and petrochemical
processes. Therefore, studies have been directed to the synthesis of transition
metal silicates to produce more stable frameworks [1,2]. Our synthetic methods
are 2-fold, namely mild hydrothermal reactions in Teflon-lined autoclaves at
100-200 ¼C using organic amines as templates and high-temperature,
high-pressure hydrothermal reactions in gold ampoules contained in a
high-pressure reaction vessel at ca. 550 ¼C and 150 Mpa using alkali metal
cations as templates. In this presentation I shall report the high-temperature,
high-pressure hydrothermal synthesis, crystal structures, and solid-state NMR
spectroscopy of several new silicates of transition metals and group 13
elements [3-5].
References
1.
Francis, R., Jacobson, A. J. (2001)
Angew. Chem. Int. Ed. 40, 2879.
2.
Wang, X., Liu, L., Jacobson, A. J.
(2002) J. Am. Chem. Soc. 124, 7812.
3.
Li, C.-Y., Hsieh, C.-Y., Lin, H.-M.,
Kao, H.-M., Lii, K.-H. (2002) Inorg. Chem. 41, 4206.
4.
Kao, H.-M., Lii, K.-H. (2002) Inorg.
Chem. 41, 5644.
5.
Hung, L.-I., Wang, S.-L., Kao, H.-M.,
Lii, K.-H. Inorg. Chem. in press.