MZ-35, a new layered pentasil borosilicate synthesized in the presence of large alkali cations

摘要

A new layered borosilicate has been synthesized in the presence of cesium and sodium cations and its structure has been solved by a combination of automated diffraction tomography (ADT) and X-ray powder diffraction (XRPD). MZ-35 has a composition NaCs2[BSi7O_(16)(OH)_2](OH)_2 4H2O and features space group P-4m2. The unusually small unit cell (a 7.3081 A, c 10.7520 A) is shared by two random-stacked configurations of the structure: a network of connected pentasil units related to the layer of RUB-18 and a bidimensional checkerboard of intersecting ladders of 4-membered rings. The two configurations are related by the simple face-sharing inversion of a hydroxyl-bearing tetrahedron.