Three new aluminoborates: from 1D tube to 3D framework.

Three new aluminoborates (ABOs) KCs[Al{B5O9(OH)}{BO(OH)2} (1), K0.5Cs[Al{B5O10}1/2{BO2(OH)}] (2), and Cs1.5[Al{B5O10}1/2{BO2(OH)}] (3) have been made under solvothermal conditions. 1 features a 1D tube constructed by the alternation of [B5O9(OH)]4− clusters and AlO4 units, onto which the [BO(OH)2]− triangles are grafted. To further construct higher dimensional structures based on the structure 1, solvents were adjusted for high basicity, resulting in the formations of the 3D ABO frameworks 2 and 3. 2 and 3 are isostructural and built from [B5O10]5− clusters, AlO4 tetrahedra and [BO2(OH)]2− triangles, in which [B5O10]5− clusters are bridged by AlO4 tetrahedra to produce a 2D ABO layer with 14-membered ring (MR) windows, and the [BO2(OH)]2− triangles act as the linkers to bridge the adjacent ABO layers to form 3D ABO frameworks containing eight types of channels. UV-vis diffuse reflectance spectra indicate that 1, 2, and 3 have potential applications in deep ultraviolet (DUV) regions. [ABSTRACT FROM AUTHOR]