Molecular structure packing analysis

The image of a single molecule, the structure of which has been determined by crystal structure analysis, shows a molecular structure, but not a crystal structure , an X-ray structure , or even worse an X-ray . The packing and the spatial arrangement of the molecules in a crystal are always an indispensable part of a crystal structure. 

Stipanovic AJ, Sarko A (1976) Packing analysis of carbohydrates and polysaccharides, 6. Molecular and crystal structure of regenerated cellulose II. Macromolecules 9 851-857... 

The crystal and molecular structure of eight different complexes was established by X-ray analysis, indicating three types of disulfide arrangements in the crystal lattice. All crystals are built up from DGTD molecules packed along the twofold symmetry axes and solvent molecules located around the twofold... 

Crystals of endo-Su (a-Sig) are intense lemon-yellow, rhombic plates and belong to the orthorhombic crystal system. The molecules are arranged to form a pseudohexagonal close packing which accounts for the higher density of the endo-Sis crystal. Crystals of exo-Sig (PSu) are monoclinic. The crystal and molecular structure data are summarized in Table 15. A detailed analysis and modeling of the intermolecular forces in 12 sulfur allotropes... 

Williams, D. E., Starr, T. L., Calculation of the crystal structures of hydrocarbons by molecular packing analysis, Comput. Chem. 1977, 1, 173. 

D. E. Williams and T. L. Starr, Computers and Chemistry, 1, 173 (1977). Calculation of the Crystal Structures of Hydrocarbons by Molecular Packing Analysis. 

Our complementary approach combines the analysis of the crystal structure with analysis of the molecular structure of the component systems, using experimental data from X-ray crystal analysis, crystal packing studies, extended Hiickel and density functional calculations, as described above. 

By mixing two solutions of M(hfac)2 M = Mn(II) and Cu(II), and 14d by a 1 2 ratio, the complexes of [M(hfac)2-(14)2] were obtained as single crystals. Similarly, the 1 1 complex of [M(hfac)2-15d] was prepared. The molecular structures and crystal packing of all complexes were revealed by X-ray crystal structure analysis. The manganese and copper ions in all complexes reside in the center of symmetry of distorted octahedrons. Molecular structures of [Cu(hfac)2-(14d)2] and corresponding aminoxyl complex, [Cu(hfac)2-(14NO)2] are shown in Figure 9. 

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