(599g) Crystallization of MIL-53 Metal Organic Frameworks (MOFs) through Changes in the Hydrothermal Process

Metal organic frameworks are a class of porous materials with highly ordered 1-,2-, or 3-dimensional networks which are formed by the coordination of metal clusters with organic ligands. Because of their large surface areas and high pore volumes and long-range order, these materials can capture molecular species and are thus may be applied to a variety of functions such as molecular storage, catalysis and separation. MIL-53 crystals are well-studied materials which belong to a subclass of MOFs with rod-packing motifs and thus 1-dimensional channels, which makes them particularly interesting for their applications to passive separation processes as size-selective separation materials. In order to demonstrate their feasibility as separation materials some challenges must be addressed. Among these are the control of crystal size and number of defects and crystal intergrowths through the hydrothermal synthesis method which is perhaps the most popular process used to produce the most robust thermodynamic MOF products. Though typically MIL-53 crystals are made as large as a micrometer in diameter, we apply principles of crystallization to make large MIL-53 single crystals, some of which may be visible to the naked eye, through the hydrothermal method. We also explain under which conditions these approaches may lead to the formation of lesser defects.