Crystal packing patterns

Crystal Packing Patterns of Cyclodextrins Are Determined by Hydrogen Bonding... 

Crystal and molecular structures of 3 bile salt hydrates have been solved [7,51,53]. The crystallographic data (Table 2) show that all are monoclinic with 2 molecules in each unit cell. Whereas the anions are held together mainly by ion-ion and ion-dipole interactions between the counterions and the carboxylate and hydroxyl groups to which water molecules contribute, the crystal packing patterns are remarkably similar (Figs. 4 and 5). The crystal packing upon looking down the b... 

CRYSTAL PACKING PATTERNS OF CYCLODEXTRIN INCLUSION COMPLEXES ... 

Figure 12.2. Crystal packing patterns in 22 2CCl4 as viewed along the crystallographic fa-axis (a) and c-axis (b). Hydrogen atoms omitted for clarity.

Figure 14-15 shows three X-ray diffraction patterns obtained from small crystalline particles of metallic copper, aluminum, and sodium. The qualitative similarity of the patterns given by copper and aluminum shows that they have the same crystal packing. Careful measurements of the spacing of the lines indicate that the atoms... 

A derived crystal packing model proved to be useful in resolving the crystal structure of a metastable polymorph of racemic modafinil, where details of the solved crystal structure of one polymorph was used as a basis for developing the structure of the other [12]. It was found that the calculated XRPD pattern matched well with the experimental data, indicating the correctness of the analysis. The powder diffraction of two polymorphs of chlorothalonil were solved to obtain... 

The structural chemistry of some metal dithiocarbamates, i.e. systematics, coordination modes, crystal packing, and supramolecular self-assembly patterns of nickel, zinc, cadmium, mercury,363 organotin,364 and tellurium,365 366 complexes has been thoroughly analyzed and discussed in detail. Supramolecular self-assembly frequently occurs in non-transition heavier soft metal dithiocarbamates. Thus, lead(II),367 bismuth(III)368 zinc,369 cadmium,370 and (organo)mercury371 dithiocarbamates are associated through M- S secondary bonds, to form either dimeric supermolecules or chain-like supramolecular arrays. The arsenic(III)372 and antimony(III)373 dithiocarbamates are... 

Kawakubo s fluorescence results 86> for methyl- and dimethylnaphthalene solids can be similarly related to the crystal structure. Both 2-and 2,6-substituted naphthalenes retain the same close-packed layer structure as seen in naphthalene. The only effect of the methyl substitution is to increase the crystal dimension along the naphthalene long axis87 . Less is known about the crystal structures of 1- and 1,6-substituted naphthalenes, except that the 1-substituent requires a different packing pattern than naphthalene and that 1- and 1,6-substituted naphthalenes have much lower melting points than the 2-substituted naphthalenes. The absence of sandwich pairs in 2- and 2,6-substituted naphthalene crystals certainly explains the lack of excimer fluorescence in the crystal spectra. Presumably, such pairs are also absent in crystalline 1-methylnaphthylene, but they seem to be present in glassy 1-methyl-naphthalene and in 1,6-dimethylnaphthalene solid. 

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