Chapter 4 - Jacobs University

Chapter 2
were block-diagonal least-squares on F 2
Experimental
for structures having more than 1200 parameters.
Routine Lorentz and polarization corrections were applied and absorption corrections were
performed using the SADABS program.
In all least-squares refinements the residuals R and R w have been calculated using the following
equations:
R = Σ ║F o │-│F c ║/ Σ │F o │; R w = [ Σ w(F o 2 -F c 2 ) 2 / Σ w(F o 2 ) 2 ] 1/2 .
2.1.3 Multinuclear magnetic resonance spectroscopy
NMR spectra were recorded on a JEOL 400 ECX spectrometer operating at 9.39 T (400 MHz for
proton) magnetic field. The resonance frequencies were 161.834 MHz for 31 P, 105.155 MHz for
51 V NMR, 19.609 MHz for 89 Y NMR, 85.941 MHz for 195 Pt NMR and 16.656 MHz for 183 W.
Chemical shifts are given with respect to external standard 85% H 3 PO 4 for 31 P, neat VOCl 3
for
51 V, 0.75M Y(NO 3 ) 3 for 89 YNMR, aqueous 2M K 2
Pt(CN) 6
for 195 Pt, 2 M Na 2 WO 4 for 183 W. All
aqueous 183 W NMR spectra were collected on highly concentrated solution.
2.1.5 Elemental and thermogravimetric analyses
All elemental analyses were performed by Analytische Laboratorien, Industriepark Kaiserau,
51789 Lindlar, Germany. Thermogravimetric analysis (TGA): Water contents were determined
using a TGA Thermalgravimetric Analyzer with 10-30 mg samples in 100 µL alumina pans,
under a 100 mL Min-N 2 flow and with heating rates of 5 o C min -1 .
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