11.03.2014 Views

Chapter 4 - Jacobs University

Chapter 4 - Jacobs University

Chapter 4 - Jacobs University

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

<strong>Chapter</strong> 9<br />

Unpublished Results<br />

Figure 9.60 TGA spectrum of complex 22a.<br />

9.3.3.1 X-ray crystallography<br />

A yellow crystal of 22a with dimensions 0.33 x 0.13 x 0.07 mm3 was mounted in a Hampton<br />

cryoloop for indexing and intensity data collection at 173 K on a Bruker D8 APEX II CCD<br />

single-crystal diffractometer using Mo Kα radiation (λ = 0.71073 Å). Of the 227743 reflections<br />

collected (2θ max = 55.86°, 98.4% complete), 12649 were unique (R int = 0.0975) and 9638<br />

reflections were considered observed (I > 2σ (I)). Routine Lorentz and polarization corrections<br />

were applied and an absorption correction was performed using the SADABS program<br />

(Sheldrick, G. M.; Acta Crystallogr. 2007, A64, 112). Direct methods were used to locate the<br />

tungsten and yttrium atoms (SHELXS-97). Then the remaining atoms were found from<br />

successive Fourier maps (SHELXL-97). The final cycle of refinement, including the atomic<br />

coordinates, anisotropic thermal parameters (W, Zr, Ge, and K atoms) and isotropic thermal<br />

parameters converged at R = 0.0502 (I > 2σ(I)) and and R w = 0.1518(all data).<br />

215

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!