Symmetry -based strategies

A very productive strategy for the synthesis of glass-forming materials is the use of highly branched rigid structures. As a suitable center for starburst molecules with a threefold symmetry, triarylamine or benzene are used most frequently. Due to the large number of starburst molecules described in the literature, we divide this class into two subgroups, compounds based on the triarylamine and the benzene centers. 

Thus, it is herein that we now describe the results of this analysis which we regard as the development of a general strategy for the construction of spherical molecular hosts. [11] We will begin by presenting the idea of self-assembly in the context of spherical hosts and then, after summarizing the Platonic and Archimedean solids, we will provide examples of cubic symmetry-based hosts, from both the laboratory and nature, with structures that conform to these polyhedra. 

This strategy is absolute in the sense that it employs symmetry properties of perfectly corresponding pairs rather than approximate models based on extrapolation, analogy, homology, or calculations from first principles. No other method is available in chemistry to provide such strong proof of internal consistency. Any measurable... 

DICVOL91 has an indexing approach based on the dichotomy method, introduced by Louer and Louer. Shirley defined this method as probably the optimal exhaustive strategy in parameter-space . The original version of the program was written for orthorhombic and higher symmetry. Later, the method was extended to monoclinic and to triclinic symmetry. ... 

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