SHELX

X-ray structural analysis. Suitable crystals of compound 14 were obtained from toluene/ether solutions. X-ray data were collected on a STOE-IPDS diffractometer using graphite monochromated Mo-Ka radiation. The structure was solved by direct methods (SHELXS-86)16 and refined by full-matrix-least-squares techniques against F2 (SHELXL-93).17 Crystal dimensions 0.3 0.2 0.1 mm, yellow-orange prisms, 3612 reflections measured, 3612 were independent of symmetry and 1624 were observed (I > 2ct(7)), R1 = 0.048, wR2 (all data) = 0.151, 295 parameters. 

Sheldrick, G. M. (1990). Phase annealing in SHELX-90 direct methods for larger structures. Acta Crystallogr. A 46, 467-473. 

Sheldrick, G. M. (2002). Macromolecular phasing with SHELXE. Z. Kristallogr. 217, 644-650. 

Some of the popular density modification programs implementing the real space restraints discussed above are Solomon (Abrahams, 1997), DM (Cowtan, 1999), RESOLVE (Terwilhger, 2003), Pirate (Cow-tan, http // www.ysbl.york.ac.uk/ cowtan/pirate/ pirate.html) and SHELXE (Sheldrick, 2002). 

G. M. Sheldrick, SHELX-76, Program for Crystal Structure Determination , University of Cambridge, 1976. 

Sheldrick, G.M. SHELXS-76, a program for crystal structure determination, University Chemical Laboratory, Cambridge, England, 1976. 

A preliminary knowledge of the crystal structure is important prior to a detailed charge density analysis. Direct methods are commonly used to solve structures in the spherical atom approximation. The most popular code is the Shelx from Sheldrick [26] which provides excellent graphical tools for visualization. The refinement of the atom positional parameters and anisotropic temperature factors are carried out by applying the full-matrix least-squares method on a data corrected if found necessary, for absorption and diffuse scattering. Hydrogen atoms are either fixed at idealized positions or located using the difference Fourier technique. 

Sheldrick, G. M. SHELXS-97, Program for Crystal Structure Determination University of Gottingen Gottingen, Germany, 1997. (b) Sheldrick, G. M. Acta Crystallogr., Sect. A 1990, 46, 467. 

Insert the file name of the foreign file in the input section. Select the file type from the Babel input list in Babel Types. For example the SHELX or CSD type would commonly be used for importing crystallographic data. 

The best approach to date to automatic structure solution is the direct method (DM), introduced by Hauptmann,154 Jerome Karle,155 and Isabella Karle,156 and made possible by efficient computer programs, such as MULTAN (Main,15 Germain,158 and Woolfson59) and SHELX... 

In addition to local programs, the following programs were used on the CICT-CII-HB DPS8 Multics systems Zalkin s Fourier Main Germain s Multan Busing, Martin and Levy s Orffe Sheldrick s Shelx Johnson s Ortep. 

Sheldrick G. M., SHELXS-86 A Program for the Determination of Crystal Structures from Diffraction Data, Univeersity of Gottingen, Germany (1990). 

X-Ray Crystallography Determination of the unit cell and data collection were performed at room temperature on an Enraf-Nonius CAD4 diffractometer, using a graphite-monochromated Mo-Ka radiation (y = 0.71073 A). The structures were solved by direct methods using Siemens SHELXS-97 and refined by least-squares procedures on Fo with SHELXL-97 by minimizing the function w(Fo -Fc ), where Fo and Fc are the... 

G. M Sheldrick, available online at http // shek.uni-ac.gwdg.de/SHELX/, accessed on C)c-tober9,2001. 

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