Synthesis and structure determination of a new microporous zeolite with large cavities connected by small pores

[EN] A new small-pore germanosilicate zeolite, named as ITQ-49, has been synthesized using a new ditetraalkylphosphonium dication as an organic structure-directing agent, and its structure has been solved by direct methods applied to the powder X-ray diffraction pattern of the calcined solid. This new zeolite crystallizes in the space group Immm with cell parameters a = 19.6007(8) angstrom, b = 18.3274(7) angstrom, and c = 16.5335(6) angstrom. The pore topology of ITQ-49 consists of large, nonspherical cavities that are connected to each other through small eight-membered-ring windows, resulting in a unidirectional small-pore zeolite that has a relatively large adsorption capacity. Also, ITQ-49 contains double four-membered-ring units where Ge is preferentially located, and fluoride anions are placed inside these units.The authors are thankful for financial support by the Spanish MICINN (MAT2009-14528-C02-01 and PLE2009-0054) and Consolider Ingenio 2010-Multicat. M.H-R. acknowledges the FPI Program of the Spanish MICINN for a predoctoral fellowship. The authors thank Dr. A. Vidal and T. Blasco for NMR assistance and useful discussions.Hernández Rodríguez, M.; Jorda Moret, JL.; Rey Garcia, F.; Corma Canós, A. (2012). Synthesis and structure determination of a new microporous zeolite with large cavities connected by small pores. Journal of the American Chemical Society. 134(32):13232-13235. https://doi.org/10.1021/ja306013k13232132351343