Extended Solid Frameworks

Owing to their larger size, coordination solids incorporating cluster cores in place of individual metal centers can be expected to have an expanded framework structure. This is of particular interest for 3D solids, wherein the expansion could produce a highly porous framework with host-guest properties similar to those of zeolites. 

Reactions similar to reaction 5 have resulted in numerous cyano-bridged cluster-containing solids, and these are enumerated in Table V. While all but a 

Hexanuclear Cluster-Cyanide Frameworks Prepared via Solution Assembly 

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Compounds isotypic with the k phases arc found among intcrmetallics, borides, carbides and oxides and also with silicides, germanides, arsenides, sulfides and sclcnides no nitrides, however, are found. The mode of filling the various voids in the metal host lattice of the k phases follows the schemein Ref. 4 and is presented in Table 1 for all those compounds for which the atom distribution is well known from x-ray or neutron diffraction. Accordingly, B atoms in tc-borides, Zr, Mo, W, Re)4B and Hfy(Mo, W, Re, Os)4B , occupy the trigonal prismatic interstices within the parent metal framework of a Mn, Aln,-type structure (see Table 1 see also ref. 48). Extended solid solutions are found for (Hf, Al)[Pg.140]

O Keeffe, M., Eddaoudi, M., Li, H., Reinecke, T., and Yaghi, O. M. (2000). Frameworks for extended solids Geometric design prinicples. J. Solid State Chem. 152, 3-20. 

The one-electron wave function in an extended solid can be represented with different basis sets. Discussed here are only two types, representing opposite extremes the plane-wave basis set (free-electron and nearly-free-electron models) and the Bloch sum of atomic orbitals basis set (LCAO method). A periodic solid may be considered constmcted by the coalescence of these isolated atoms into extended Bloch-wave functions. On the other hand, within the free-electron framework, in the limit of an infinitesimal periodic potential (V = 0), a Bloch-wave function becomes a simple... 

IN THIS PART of the book, we shall attempt to describe solids in the simplest meaningful framework. Chapter 1 contains a simple, brief statement of the quantum-mechanical framework needed for all subsequent discussions. Prior knowledge of quantum mechanics is desirable. However, for review, the premises upon which we will proceed are outlined here. This is followed by a brief description of electronic structure and bonding in atoms and small molecules, which includes only those aspects that will be directly relevant to discussions of solids. Chapter 2 treats the electronic structure of solids by extending the framework established in Chapter 1. At the end of Chapter 2, values for the interatomic matrix elements and term values are introduced. These appear also in a Solid State Table of the Elements at the back of the book. These will be used extensively to calculate properties of covalent and ionic solids. 

The term building unit is used extensively in the literature of extended and framework hybrid solids. In general, this term, whether modified by primary or secondary, refers to the basic inorganic repeat unit that when polymerized, forms the foundation of the inorganic component of the structure. In aluminosilicate... 

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