NON-SILICA-BASED MESOSTRUCTURED MATERIAL. 2 - SYNTHESIS OF HEXAGONAL SUPERSTRUCTURE CONSISTING OF 11-TUNGSTOPHOSPHATE ANIONS AND DODECYLTRIMETHYLAMMONIUM CATIONS

A new mesostructured material (denoted WP) constructed from lacunary K eggin anions PW11O397- and surfactant cations CH3(CH2)(11)N(CH3)(3)(+) has been hydrothermally synthesized. The optimum conditions for the s ynthesis of WP were 1.0 Na2WO4. 2H(2)O:0.5 H3PO4:1.0 CH3(CH2)(11)N(CH3 )(3)Br:83.3 H2O, pH 8.0-8.5, 403 K, and 6 h. WP could also be synthesi zed by using H3PW12O40. nH(2)O heteropoly acid as a starting material under similar reaction conditions. The XRD and TEM measurements reveal ed that WP has a regular hexagonal superstructure. The dimensions of t he unit cell determined by XRD were a=b=3.85 and c=1.57 nm. On the bas is of FT-IR, P-31 MAS NMR, TG-DTA, ICP, and elemental analysis studies , the chemical formula of WP was determined to be [CH3(CH2)(11)N(CH3)( 3)](6)NaPW11O39. 5.7H(2)O. A model with the wall of lacunary Keggin an ions PW11O397- and the micelles of surfactant cations has been propose d. (C) 1998 Elsevier Science B.V. All rights reserved.