There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Crystalline metal-organic frameworks (MOFs) are formed by reticular synthesis, which creates strong bonds between inorganic and organic units. Careful selection of MOF constituents can yield crystals of ultrahigh porosity and high thermal and chemical stability. These characteristics allow the interior of MOFs to be chemically altered for use in gas separation, gas storage, and catalysis, among other applications. The precision commonly exercised in their chemical modification and the ability to expand their metrics without changing the underlying topology have not been achieved with other solids. MOFs whose chemical composition and shape of building units can be multiply varied within a particular structure already exist and may lead to materials that offer a synergistic combination of properties.

The Chemistry and Applications of Metal-Organic Frameworks

J. Appl. Cryst.の発刊に際して

The long-standing challenge of designing and constructing new crystalline solid-state materials from molecular building blocks is just beginning to be addressed with success. A conceptual approach that requires the use of secondary building units to direct the assembly of ordered frameworks epitomizes this process: we call this approach reticular synthesis. This chemistry has yielded materials designed to have predetermined structures, compositions and properties. In particular, highly porous frameworks held together by strong metal-oxygen-carbon bonds and with exceptionally large surface area and capacity for gas storage have been prepared and their pore metrics systematically varied and functionalized.

/pdf/reticular-synthesis-and-the-design-of-new-materials-lazbx7tdux.pdf

Reticular synthesis and the design of new materials

From molecules to crystal engineering: supramolecular isomerism and polymorphism in network solids.

Independent one-, two-, and even three-dimensional nets interpenetrate each other in many solid-state structures of polymeric, hydrogen-bonded nets and coordination polymers. For example, the interpenetration of the adamantane units of two diamondlike nets is shown on the right. A detailed and systematic examination of many interpenetrating nets of this kind is made, and implications for crystal engineering are discussed.

Interpenetrating Nets: Ordered, Periodic Entanglement.

Structure and magnetism of coordination polymers containing dicyanamide and tricyanomethanide

A set of terms, definitions, and recommendations is provided for use in the classi- fication of coordination polymers, networks, and metal-organic frameworks (MOFs). A hier- archical terminology is recommended in which the most general term is coordination poly- mer. Coordination networks are a subset of coordination polymers and MOFs a further subset of coordination networks. One of the criteria an MOF needs to fulfill is that it contains poten- tial voids, but no physical measurements of porosity or other properties are demanded per se. The use of topology and topology descriptors to enhance the description of crystal structures of MOFs and 3D-coordination polymers is furthermore strongly recommended.

/pdf/terminology-of-metal-organic-frameworks-and-coordination-ha0o04iyzo.pdf

Terminology of metal–organic frameworks and coordination polymers (IUPAC Recommendations 2013)

Recent examples of interpenetrating and self-penetrating networks are highlighted in a discussion of interpenetration topology. A web site (http://web.chem.monash.edu.au/Department/Staff/Batten/Intptn.htm) has been set up which contains a tabulated list of all known examples of interpenetration.

Topology of interpenetration

The construction of coordination networks with novel topologies and porous structures that provide new sizes, shapes, and chemical environments is of great interest in recent years, due to their intriguing structural diversity and potential for many applications. 2] In recent years many porous metal– organic frameworks with unique structures have been obtained and their adsorption properties were widely investigated, however, those with specially shaped channels such as 1D helices are rare. Metal–ligand coordination has been well used in the directed assembly of extended porous metal–organic networks, and one of the key points for such studies is the design or choice of components that organize themselves into desired patterns with useful functions. In this regard, considerable attention has been devoted to the networking ability of isonicotinic acid (1) and its derivatives, which are multifunctional ligands potentially able to act as bridging ligands to produce open lattice species with various structural topologies and large pores. In this study, we choose an analogy of 1, 9-acridinecarboxylic acid (HL), whose coordination chemistry has not been previously investigated, as a bridging ligand to construct new framework materials with novel structures and special properties based on combining its bridging coordination ability with its steric bulk. Although the coordination sites of HL and 1 are very similar, their coordination chemistry are found to be quite different due to the bulk of HL. We report herein a 3D twofold interpenetrating NbO-type network [Cu2(m2OMe)2(L)2·(H2O)0.69]n (2) with 1D channels.

Stuart Robert Batten

Papers

Interpenetrating Nets: Ordered, Periodic Entanglement.

Structure and magnetism of coordination polymers containing dicyanamide and tricyanomethanide

Terminology of metal–organic frameworks and coordination polymers (IUPAC Recommendations 2013)

Topology of interpenetration

A Neutral 3D Copper Coordination Polymer Showing 1D Open Channels and the First Interpenetrating NbO‐Type Network