Solid-state structures atomic-molecular crystals

At the end of the process, one obtains a large amount of information regarding the solid-state structure of a compound. Its three-dimensional structure and molecular conformation become known, as do the patterns of molecular packings that enable the assembly of the crystal. In addition, one obtains complete summaries of bond angles and bond lengths for the molecules in the crystal as well as detailed atomic coordinates for all of the atoms present in the solid. One generally finds... 

The crystal and molecular structures of two spiroarsoranes of type XXI (R = Ph, R = R" = CH3 and R = OH, R = R" = H) have been determined by single-crystal X-ray diffraction analyses (68, 69). The crystal data for these compounds are summarized in Table V. Both compounds have a geometry at the arsenic atom that lies on the Berry coordinate between rectangular-pyramidal and trigonal-pyramidal. These structures show close parallels between the structures of related arsenic and phosphorus systems. It has been concluded that, since the solid-state structures of these compounds lie close to the Berry coordinate, the dynamic process in solution is distortion along that coordinate (68, 69). 

Figure 12.3 A single crystal X-ray stmcture of the Jt-expanded borazine macrocycle 12.8 (Scheme 13.4). (a) Sketch of the super-structure, viewed along the c-crystallographic axis and (b) graphical illustration of the molecular conformation in the solid state. Carbon atoms are shown in gray, nitrogens in blue, and borons in green. Hydrogen atoms and solvent molecules have been omitted for the sake of clarity.

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