Crystalline state single crystals

Diamagnetic AuCls is dimeric in the vapor as well as in the crystalline state. Single crystals can be obtained by sublimation at temperatures above 100°C. At 200°C thin cellophane-like crystals parallel to (100) form whereas at 250-280° sublimation yields a lacy network of wine-red [001] needles within thin orange... 

TheA tr is determined by the increase in degrees of freedom for spatial conformation changes in the liquid state as compared to the crystalline state. In crystal lattices, spatial conformation change resulting from the rotation about a Lexible bond is not permitted. Such a rotation, however, is possible in the liquid state. For each Lexible bond, there are three possible conformations due to steric constrain. Thus, the probability of each conformation resulting from one single bond is one-third, and the probability of the fully stretched conformation is... 

Structural changes produced by the Norrish-Yang reaction proceeding in two crystal forms of (12) can be monitored by X-ray structure analysis. The (i ,5)-cyclobutenol (13) is obtained as single photoproduct from the corresponding isopropylbenzophenone derivative, via diastereospecific Norrish type II photocyclization in the crystalline state. The crystal packing is retained during the photoreaction. 

Many of the investigated mesogenic compounds show solid state polymorphism. In order to obtain useful information about the arrangement of the molecules in the mesophase from the X-ray data of the single crystals, it is important to investigate the crystal structure of those solid phase which transforms into the liquid crystalline phase. For instance, only the crystal structures of the low temperature solid phases of the compounds MBBA [138, 139], MHPOBC [159], and T15 [81] could be determined, but the... 

As a function of the surface potential the electron work function for a given material depends on the state of the surface of that material (adsorption, the presence of surface compounds, etc.). For crystalline substances (see Table 3.1), various crystal faces have various electron work function values, which can be measured for single crystals. For poly crystalline substances, the final value of the electron work function depends on the contribution of the individual crystal faces to the entire area of the phase and the corresponding electron work functions the final value of the work function, however, is strongly dependent on the experimental method used for the measurement. 

Among crystalline solids, typical second-order transitions are associated with abrupt intermolecular conformational, rotational, and vibrational changes and/or with abrupt changes in crystalline disorder and/or defects [7], These changes in crystalline solids are sometimes difficult to assign without the use of appropriate spectroscopic techniques such as solid-state NMR or a diffraction procedure such as single-crystal X-ray diffraction. 

Tin incorporated mesoporous Sn-MFI catalysts with different Si/Sn ratio using microwave were synthesized with carbon as hard template. These tin MFI catalysts were characterized using various physicochemical techniques XRD reviled the formation of more crystalline MFI structures which was further supported by the SEM and TEM imaging which clearly showed well ordered zeolite single crystals with mesoporosity. The N2 sorption isothers reviled the formation of bimodal mesoporous zeolites and the presence of tin in tetrahedral site was confirmed by FTIR (970 cm 1) and XPS (3ds/2 and 3 dj 2 electronic states). The thus synthesized mesoporous Sn-MFI catalysts with different Si/Sn ratios were used in studying the catalytic Baeyer-Villiger Oxidation (BVO) of cyclic ketones... 

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