Crystal structures structure-conductivity correlations

Abstract In this chapter, recent progress in the synthesis, crystal structures and physical properties of monomeric phthalocyanines (Pcs) is summarized and analysed. The strategies for synthesis and modification of Pcs include axial coordination of central metal ions, peripheral substitution of Pc rings and the ionization of Pcs. The crystal structures of various typical Pcs, especially the effects of different synthetic and modification strategies on the supramolecular assemblies of Pcs via %—% interactions between Pc rings, are discussed in detail. Finally, the UV-vis spectroscopic, conducting, magnetic and catalytic properties of some Pcs with crystal structures are presented briefly, and the correlations between various properties and the molecular structure discussed. 

Although there exist many other correlations of the type structure conductivity, discussed in other chapters of this book (see also Refs. 4 to 11), none of them can be used for real design of a crystal lattice. We limit ourselves to a consideration of the possibility to construct molecules with a built-in tendency to give a crystal lattice required for a high metallic conductivity. 

We conducted spectroscopic examinations designed to determine the most hydrophobic region in the DHEA molecule. Our intention was to derive this knowledge from the correlations of carbon-carbon bond length from x-ray crystal structure work on sublimed DHEA with >3c->3c and 3C- H spin-spin coupling data obtained from NMR investigation of DHEA. Our initial structure work involved the x-ray study which is described as follows. 

Alternatively, the relation between structure and conductivity in both ordered and disordered compounds can be investigated using molecular dynamics (MD) simulations. In principle, MD simulations will lead to comprehensive structural and dynamic informatimi within the limitations imposed by the system size, the simulated period, and the agreement of the employed interaction potential parameters with reality. Both diffraction data (crystal structures for crystalline compounds, RMC fits for glasses) and MD approaches are valuable tools to obtain insight into the conductimi mechanism and its correlation to the atomic stmcture, though in the case of MD simulatimis it has to be verified that the force field chosen for the simulations leads to structure models that are cmisistent with experimental information. 

---