Inverted metal-organic frameworks: solid-state hosts with modular functionality

Metal-organic frameworks (MOFs) are crystalline inorganic-organic hybrid materials that consist of metal ions and organic molecules connected in space to produce an infinite one-, two-, or three-dimensional framework. The modularity of MOFs, specifically, the ability to modify the organic and/or inorganic components, offers a ready means to modify and control properties of such materials (e.g. inclusion, magnetism). This review highlights the design and synthesis of cavity-containing and porous MOFs with emphasis on methods that enable the functionalization of interior void spaces with organic groups. A relatively new class of MOFs, known as inverted metal-organic frameworks (IMOFs), which enables organic functionalization using principles of supramolecular chemistry, is discussed. We also briefly outline methods to functionalize the interior spaces of mesoporous materials (MCMs) and zeolites, and suggest that MOB offer a diverse space within which to place a wide range of organic functionalities. (C) 2003 Elsevier B.V. All rights reserved.