Crystal structure and MAS-NMR study of rehydrated UiO-7

Abstract

Abstract The framework of rehydrated UiO-7 has the ZON type of topology. The crystal structure is described on the basis of high resolution, synchrotron powder X-ray diffraction data. The chemical composition of the unit cell is Al 32 P 32 O 128 ·62H 2 O. Its dimensions are a =14.4930(2), b =14.8731(2) and c =17.5738(3) A; space group Pbca . Of the four non-equivalent Al atoms, two have normal tetrahedral coordination, whereas one obtains five-coordination and one achieves octahedral coordination on additional bonding to three non-equivalent water molecules. Six more water molecules are located in the channels and are interconnected via hydrogen bonds. These features were confirmed by solid-state 27 Al MAS NMR data. Site assignment of 31 P signals is discussed on the basis of POAl angles and Al-coordination.