Property-Structure Principles

Contents Introduction. — Structural Principles. — Synthesis and Reactions of Macromoiecular Compounds. — The Properties of the Individual Macromolecule. — States of Macromoiecular Aggregation. 

Structural Principles of Lipopolysaccharides and Biological Properties of Synthetic Partial Structures... 

Establishment of the structures of the lanthanide higher oxides, finding the structural principles involved, and attempts at understanding the relationship between their structures and properties have been under way for five decades. 

The lanthanide higher oxides have not only peculiar thermodynamic properties, but also unique physical and chemical properties. The physical and chemical properties are presented as a macroscopic parameter, such as the electrical conductivity, the coefficient of expansion, and the conversion rate of a catalysis process. Due to the lack of knowledge of the wide range of non-stoichiometry of the oxygen-deficient fluorite-related homologous series of the lanthanide higher oxides, the macroscopically measured data of the physical and chemical properties are scattered, and therefore, based on the structural principle of the module ideas a deep understanding the relationship between the properties and structures is needed. 

Moreover, to understand why SF6 exists as a stable compound whereas SC16 does not, we need to know something about the properties of the S, F, and Cl atoms. As another illustration, it may be asked why the P043- ion is quite stable but N043 is not. Throughout this descriptive chemistry book, reference will be made in many instances to differences in chemical behavior that are based on atomic and molecular properties. Certainly not all chemical characteristics are predictable from an understanding of atomic and molecular structure. However, structural principles are useful in so many cases (for both comprehension of facts and prediction of properties) that a study of atomic and molecular structure is essential. 

At an early stage of the development, the structural information was rather fragmentary. Nowadays, however, the accumulation of structural data for isomers has enabled us to understand structural principles and the optical properties of chelate complexes in considerable detail. In this connection, column chromatography on SP Sephadex has played an important role in the separation of isomers of coordination compounds (2). In view of the large number of structures, a few basic series of structures will be taken up and discussed. 

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