Seeking structural flexibility

In the search for new markets manufacturers have been creating new kinds of cars by merging existing model types. The SUV has merged with the MPV and the MPV with the microcar. As society becomes more complex, and niche markets more specialized, manufacturers seek new formats to meet the needs of lifestyle shifts. There is an awareness that cars play an important role in the formation of personal or group identity. Several recent concept cars are structured in new ways with doors opening in a novel manner and interiors with a high level of flexibility. 

Alloy with Memory. In seeking a way to reduce the brittleness of titanium, U.S. Navy researchers serendipitously discovered a nickel-titanium alloy having an amazing memory. Previously cooled clamps made of the alloy (nitinol) are flexible and can be placed easily in position. When warmed to a given temperature, the alloy hardware then exerts tremendous pressure. Use of conventional clamps for holding bundles of wires or cables in a ship or aircraft structure requires special tools. For this and other applications in industry and medicine, nitinol has been in demand. The alloy, however, is not easy to produce because only minor variations in composition can affect the snap back" temperature by several degrees of temperature. 

Polymorphs are classified according to the following terminologies. Concomitant polymorphs crystallize simultaneously from the same solvent and crystallization flask under identical crystal growth conditions. They may be viewed as supramolec-ular isomers in a chemical reaction. Conformational polymorphs occur for flexible molecules, i.e. these molecules can adopt more than one conformation under ambient conditions. When different conformers of the same molecule are present in the same crystal structure the situation represents conformational isomorphs. Conformational isomorphism, the existence of multiple conformations in the same crystal structure, is closely related to the presence of more than one molecule in the asymmetric unit, i.e. Z >1. The exact reasons why some crystals have Z > 1 are still not properly understood even as several research groups are working to seek answers to this enigma [9]. Pseudopolymorphism, [10] the occurrence of the same molecule with different solvent molecules in the crystal lattice or the same solvent in a different stoichiometry, is closely related to polymorphism. 

Recently we have been seeking new types of organosilicon polymers with the hope of finding polymers having unique structures and interesting combinations of properties. Out of this work has come a new siloxane that is, at least in part, inherently fibrous. The fibers characteristic of it have very small diameters and are flexible and inert. 

One facet of structure that has aroused considerable attention is the matter of the flexibility of the polymeric chains and the pendant phosphines. The possibility of interaction between two or more sites along the same or different chains is partially dependent upon this. Intuitively, one would think that as the degree of cross-linking increased the flexibility of the chains would decrease, effecting a restriction in interactions between sites. This has important consequences both in synthesis and catalysis. In catalysis, site-site interactions can lead to, for example, dimeric metal species that may have much reduced activities in comparison to those of monomeric complexes. One obviously would seek to design a matrix that would avoid site-site interaction for such catalysts. Quite a number of experiments have... 

Working with people with EUPD is hard, and there are no easy answers or treatment tenplates. Plan for structure, but be flexible, and if you think you re getting into a battle of wills , step back and seek senior support. 

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