Macromolecules inorganic

The tendency of atoms of certain elements to form chains with themselves (homoatomic catenation) or in alternation with other atoms (heteroatomic catenation) is of extreme importance in chemistry. The immense subject of organic chemistry and, indeed, life as we know it depend on the special ability of carbon to catenate from the chemical engineering standpoint, catenation and the associated ability to form molecular rings and cages provide opportunities to make materials of desired mechanical, electrical, thermal, chemical, or catalytic properties. 

Condensation polymerization, in which some very stable molecule XZ is eliminated from equimolar amounts of species RXE—X and RXE—Z (E being the element that catenates and R some side group), is more widely applicable  

The success of reaction 3.2 in producing long-chain polymers depends on having precisely equimolar amounts of the two pure reactants, and essentially complete reaction otherwise, small polymeric molecules (oligomers) will be produced instead. Accordingly, a rather more effective variant of reaction 3.2 has X and Z in the same molecule  

Carbon, having a normal valence of four, readily forms elaborate branched chains, rings, and networks (organic molecules). In the limiting case, the 

Nevertheless, synthetic diamonds have been made by the high tempera-ture/high pressure route, first by Allmanna Svenska Elektriska Aktiebolaget 

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In conclusion, some trends can be gleaned from an examination of the content of the symposium as a whole. The growth in research efforts addressing the synthesis and properties of poly(diorganosilanes) will likely continue. The unique photophysical properties of this newly developed class of inorganic macromolecules (12) together with ready synthetic routes will be contributing forces here, and no doubt new vectors will arise. 

Polyphosphazenes comprise some of the most intensively studied inorganic macromolecules. They include one of the oldest known synthetic polymers and many of the newest. In molecular structural versatility, they surpass all other inorganic polymer systems (with over 300 different species now known), and their uses and developing applications are as broad as in many areas of organic polymer chemistry. 

The development of synthetic routes to new polyphosphazene structures began in the mid 1960 s (2-4). The initial exploratory development of this field has now been followed by a rapid expansion of synthesis research, characterization, and applications-oriented work. The information shown in Figure 3 illustrates the sequence of development of synthetic pathways to polyphosphazenes. It seems clear that this field has grown into a major area of polymer chemistry and that polyphosphazenes, as well as other inorganic macromolecules, will be used increasingly in practical applications where their unique properties allow the solution of difficult engineering and biomedical problems. 

The synthesis of poly(organophosphazenes) represents probably the best example of a central theme of Inorganic macromolecules Preparation of a reactive polymeric intermediate, poly(dichlorophos-phazene), and subsequent use in a wide variety of side group replacement reactions (Figure 1). This concept has been demonstrated in a number of laboratories (3) and has provided a wide variety of polymers with different properties. 

Specific inorganic macromolecules are unusual because they can be hydrolyzed to relatively innocuous products or to small molecules that can be metabolized. Most conventional organic polymers do not have this attribute. Thus, these inorganic systems are of special interest as carrier molecules in chemotherapy. 

Physical interaction of metal complexes/ chelates/ clusters with organic and inorganic macromolecules... 

It might be expected that transposing the synthetic methods that have worked so well for the preparation of organic polymers would allow similarly facile access to inorganic macromolecules. However, consideration of the main synthetic routes to organic polymers (Scheme 8.1) illustrates the problems associated with this approach. 

Polyphosphazenes are inorganic macromolecules containing a phosphorus-nitrogen backbone with each phosphorus atom having two pendant side groups. Polyphosphazene derivatives were prepared by nucleophilic displacement of either fluoroalkoxy or chloro substituents using a nucleophile that consisted of a ketal alkoxide, which was subsequently oxidized using concentrated nitric acid or an azido alkoxide. 

Polyphosphazenes comprise by far the largest class of inorganic macromolecules. At least 700 different polymers of this type have been synthesized, with a range of physical and chemical properties that rivals that known hitherto only for synthetic organic macromolecules.1... 

Methods are now available for the hybridization of phosphazenes with other polymer systems in order to combine the special properties of the inorganic macromolecules with those of... 

Carbon nanotubes (CNTs) are considered to be all-carbon inorganic macromolecules which generally consist of one or more graphene sheets seamlessly wrapped into cylinder-shaped tubes, corresponding to single-walled carbon nanotubes... 

The field of chemistry was benchmarked by an ad hoc panel of 13 members, 12 from the United States and one from Switzerland, with expertise across the 11 selected areas covered in the report, which are analytical, atmospheric, biological, chemical education, inorganic, macromolecules, materials and nanoscience, nuclear/radiochemistry, organic, physical, and theory/computation. The panel was charged with addressing three questions ... 

This book provides an overview of possible combinations of metal complexes and metals with organic and inorganic macromolecules (often also named macromolecular metal complexes — MMC [1]). This book covers the formation, synthesis, structure and properties of these exciting and relatively new materials. Metal-containing macromolecules are a fascinating field of science. It is readily understandable that materials with unusual properties are obtained by having a metal complex or metal as part of a macromolecule. Nature shows us the functions of such materials extremely well by the selectivity and activity of, for example, hemoglobin, photosynthesis and metalloenzymes. 

After some definitions in Section 1.1, the classifications of metal complexes and metals in macromolecules in four types of combination are given in Section 1.2. A summary of metal complexes in nature and the history of artificial ones is presented in Section 1.3. Then Section 1.4 introduces important properties of these materials. A short review of other inorganic macromolecules - without metal - not dealt with in detail in this book is presented in Section 1.5. 

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