MOF family

Figure 4.1 clearly illustrates the modular construction of MOFs, with ligands used as pillars and metal clusters as node points. One unique feature of MOFs seems to be the possibihty to systematically modify their lattice. For instance, by replacing the terephthalate ligands of MOF-5 (Figure 4.1) with different dicarboxylate ligands, a family of isoreticular metal-organic frameworks (known in literature as the... 

MOF Males-absent on the first. A MYST family HAT subunit of the Drosophila MSL dosage-compensation complex and a highly homologous human complex. 

MYST HATs A family of acetyltransferases named after its founding members MOZ, Ybf2/Sas3, Sas2 and Tip60. Human MYST HATs include MOZ, Tip60, MOZ/MORF, HBOl and MOF. 

The number of newly described metal organic frameworks (MOFs) exploded in the past decade. Since the MOFs are not strictly zeolites that family of materials is not discussed here. The reader is referred to several current reviews of the field [85]. 

One of the best studied families of porphyrins for use as metalloligands is comprised of metalated 7e50-tetra(p-carboxyphenyl)porphyrins (TCPPs). Several reviews have discussed the synthesis and properties of TCPP CPs and MOFs (38, 102, 103). As with other supramolecular structures, the structures of these TCPP MOFs are dictated by the geometries of their nodes. Typically, TCPP MOFs have two types of nodes the four-connected, approximately square-planar porphyrins, and the SBUs, which can have various geometries but... 

It has been tried to put the result of Kennedy et al (//) in a la-Mw graph (Fig. 7). Two samples families are distinguished quenched samples and slowly crystallized samples. In both families, the ductile-brittle transition occurs at lac = 6 nm. The corresponding critical molar mass defined in scheme A is higher for slowly crystallized samples (M c 100 kg.mof ) than for quenched ones (M c 60 kg.mof ). This result can be considered as a proof that scheme B is more pertinent than scheme A. 

The boat-boat (417) and the twist-boat-boat (418) have low torsional strains but severe non-bonded repulsions, which, as usual, are transferred to internal angle strains. However, heteroatoms can modify these repulsions and certain transannular interactions can drastically reduce them. Even so, the boat-boat family is relatively unimportant as its energy is calculated to be quite high (12 kJ moF ) in cyclooctane. Itprobably serves as an interme< ate for certain conformational interconversions of the boat-chair, especially when the twist-boat-chair pseudorotation itinerary is of high energy. In cyclooctane the boat-boat and its twisted partner have nearly the same energies and are not separated by a significant barrier. 

Trioxocane exists as a 1 1 mixture (i.e. AC = 0) of a boat-chair and a crown family conformation with an interconversion barrier of 36 kJ moF (72JA1390,1389). The ring inversion barrier in the boat-chair is 28 kJ moF but the barrier to pseudorotation has not been determined. One set of force-field calculations shows that the BC-1, 3, 6 (435) is of... 

From natural zeolites to the recently discovered meso- and macro-porous materials, the ordered porous frameworks are all constructed by inorganic species. However, in the past ten years, a new family of porous compounds composed of metal-organic frameworks (MOFs) has attracted enormous attention. The main reason is that the poor thermal and chemical stability of MOFs has been somewhat improved. In addition, the discovery of some advantages of MOFs that are lacking in molecular sieves and mesoporous materials has also stimulated the research on MOFs. 

Classification of MOFs has been studied extensively, yet this complementary approach is offered in an effort to focus on local geometry and explore the identity of any SBUs present. Topological studies tend to treat the BUs (secondary or otherwise) as nodes and focus less on the composition of the nodes themselves. This scheme is thus an effort to remain cognizant of the inorganic components of these structures as SBU variety may ultimately be considered a desirable or even tunable characteristic of this family of materials. 

Table II includes a representative sampling of a number of Ln-MOFs and CPs built from aromatic linker molecules. Note that this class of materials is dominated by the benzene-carboxylate (and related) species as shown in Fig. 16. This is an attractive linker for a number of reasons, including its planarity and rigidity that to a first assumption, may suggest a more restricted structural diversity when compared to (e.g.) the aliphatics. Despite these features, however, no less rich coordination chemistry or resultant topologies in this family are seen.

Figure 9.15 Nitrogen physisorption isotherms measured at 77 K for different MOFs. The isotherms display type I behavior expected for materials with uniform micropotes. The development of MOF materials has led to an impressive increase in the apparent sitrface areas as compared to the early measurement of the first isotherm for this family of materials. (Reproduced with permission from J. L. C. Rowsell and D. M. Yaghi, Microporous Mesoporous Mater. 2004, 73, 3. Copyright 2004 Elsevier.)...

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