A Molecular View of Elements and Compounds

Some general comments on the solid-state chemistry ( From a molecular view on solids to molecules in solids ) have been reported by Simon (1995) emphasis was especially placed on the structural chemistry of metal-rich compounds formed by the metals in groups 1 to 6 and it was underlined that it is largely based on discrete and condensed clusters. In the chemistry of metals in low oxidation states, the residual valence electrons can be used for metal—metal bonding. Metal-rich compounds lie between normal valence compounds and the elemental metals themselves, with respect to their compositions, and often also with respect to their structures fragments of usual metal structures (close-packed, b.c.c., etc.) are often component units in the structures of metal-rich compounds. 

A -Alkanoyl-A -alkylglycamines are complex polyfunctional molecules, and numerous analogs can be imagined. C12MG may be taken as the core structure, since the most information by far is available on this compound. Three kinds of structural variants of have been synthesized (Scheibel). Physical studies have been carried out on selected compounds that provide a broad view of how molecular structure influences selected physical properties. The structural elements investigated include ... 

The authors feel that compounds need to be sufficiently complex in order to provide a significant level of information content. On the other hand, compounds that are too complex may be viewed as undesirable. A number of measures for characterizing molecular complexity have been developed over the years. Complexity has been defined in terms of size, elemental composition, topology, symmetry, and functional groups present in a molecule (17,18). In the present work, we have applied a simple, chemically intuitive measure developed by Barone and Channon (18). This approach is based on a simple additive model, where values are assigned to specific classes of molecular features such as the types of atoms and bonding patterns, and the number and types of rings. This is illustrated in Eq. 2.1 ... 

Figure 3.5 Chemists use the structural formula to show a visual layout of the elements and bonds present in a compound. The molecular model shown here provides a three-dimensional view of the arrangement of atoms in a compound as expressed by the compound s chemical formula. For example, the molecular formula of the methane molecule above illustrates the chemical formula CH. ...

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