Crystal architecture

Metallic behavior down to low temperatures was reported on a compacted pellet of TI2PC [46] with very high conductivity of ctrt 10" S cm (four-probe method using indium lead wires). A specific three-dimensional crystal architecture of TI2PC is anticipated to form a three-dimensional semimetallic band. However, the... 

Malpezzi, L. et al., Crystal architecture and conformational properties of the inclusion complex, neohesperidin dihydrochalcone-cyclomaltoheptaose (p-cyclodextrin), by x-ray diffraction, Carbo-hydr. Res., 339, 2117, 2004. 

Eds., Kluwer Academic Publishers, Dordrecht, 1996 V. G. Videnova-Adrabinska, The Hydrogen Bond as a Design Element of the Crystal Architecture. Crystal Engineering from Biology to Materials, Oficyna Wydawnicza Politechniki Wroclawskiej, Wroclaw, Poland. 

Ermer, O., Eling, A., Molecular recognition among alcohols and amines - super-tetrahedral crystal architectures of linear diphenol-diamine complexes and aminophenolse. J. Chem. Soc., Perkin Trans. 21994, 925-944. 

T. Caronna, R. Sinisia, M. Catellani, S. Luzzati, L. Malpezzia, S. V Meillea, A. Melea, C. Richter, R. Sinisi, Molecular Crystal Architecture and Optical Properties of a Thiohelicenes Series Containing 5, 7, 9 and 11 Rings Prepared via Photochemical Synthesis, Chem. Mater. 2001, 33, 3906-3914. 

Controlling crystal architecture in molecular solids the supramolecular approach... 

Practical considerations may also arise. Supramolecular functionality introduced to control crystal architecture must be added without degrading the fundamental molecular properties of primary interest. Co-crystals offer an alternative approach for controlling crystal architecture without necessarily modifying the primary molecule of interest. In addition, we must recognize the role of the solvent from which the crystal grows. The occurrence of solvates and polymorphs, particularly relevant in the pharmaceutical industry, is still a relatively poorly understood aspect of crystal chemistry. The manner in which synthons are modified from normal geometries in non-crystalline organic structures is also yet to be explored fully. 

The y-crystalline form of i-PP has been studied through best fitting of X-ray diffraction powder profile [9, 10]. A novel crystal architecture was found where layers of parallel helixes two chain wide (bilayers) present a chain axis orientation with a tilt of 80° with respect to the one of the adjacent bilayers. This packing can explain several experimental results and is consistent with the model proposed for the interface between parent and daughter lamellae in branching a-form of i-PP [11, 12]. 

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