SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF SODALITES WITH ACETATE AND FORMATE GUEST ANIONS, [NA-4(CH3COO)](2)[A1(3)SI(3)O(12)](2) AND [NA-4(HCOO)](2)[AL3SI3O12](2), AND THEIR INTRACAGE OXIDATION-PRODUCT [NA-5(CO3)][NA-3-SQUARE][AL3SI3O12](2)1

Single-crystals of sodium acetate sodalite [Na-4(CH3COO)](2)[Al3Si3O12 ](2) (1) and polycrystalline material of sodium formate sodalite [Na-4 (HCOO)](2)[Al3Si3O12](2) (2) were synthesized under hydrothermal condi tions. The interactions between the organic anions, Na cations, and th e aluminosilicate sodalite framework, as well as the intracage reactiv ity of the enclathrated anions versus oxidation were investigated. The refore, the crystal structures of 1 and 2 were refined based on single -crystal and powder X-ray diffraction data, respectively. Additionally , the compounds were characterized by thermoanalytical methods as well as infrared and multinuclear MAS NMR spectroscopy. 1 and 2 crystalliz e with the cubic space group <P(4)over bar>3n (Z = 1) and the cell con stants (roam temperature) a = 9.077(2) Angstrom and a = 8.960(2) Angst rom, respectively. The 1:1 aluminosilicate host framework of 1 and 2 i s a strictly alternating array of corner-linked AlO4 and SiO4 tetrahed ra. Each [4(6)6(8)] polyhedral void is occupied by four Na+ cations, l ocated close to oxygen atoms of the six-membered rings of the framewor ks, and by one organic anion (CH3COO- or HCOO-) at the center. When 1 and 2 are annealed in air or oxygen at 1123 K and 923 K, respectively, intracage oxidation of the anion takes place without decomposition of the host framework, resulting in both cases in the same new sodalite phase which contains carbonate anions as a guest species. Sodium carbo nate sodalite, [Na-5(CO3)][Na-3 square][Al3Si3O12](2) (3), is cubic wi th the cell constant a = 9.040(3) Angstrom (room temperature) and the space group P23 (Z = 1). A Rietveld refinement based on powder X-ray d iffraction data revealed that the sodalite cages of 3 are filled alter natively with [Na-5(CO3)] and [Na-3 square] complexes in an ordered ma nner.