Studies of cis-[PtCl2(PPh2nPr) (BzS{O}Bz)] by solid-state CP/MAS 31P NMR spectroscopy, single-crystal X-ray diffraction and X-ray powder diffraction: Investigation of a question concerning polymorphism versus space group ambiguity
✍ Scribed by Julian A. Davies; Sylvain G. Dutremez; A. Alan Pinkerton
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 359 KB
- Volume
- 31
- Category
- Article
- ISSN
- 0749-1581
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✦ Synopsis
Abstract
The ^31^P CP/MAS NMR spectrum of cis‐[PtCl~2~(PPh~2~ ^n^Pr)(BzS{O}Bz)] was found to exhibit two central resonances with appropriate couplings to ^195^Pt, despite the fact that a single‐crystal x‐ray diffraction study indicated that the complex crystallized in the monoclinic space group __P__2~1~/n with Z = 4, i.e. that there is only a single crystallographically unique phosphorus atom. The possibility that the 2~1~ screw axis was absent (i.e. that the space group was actually Pn) was examined by a reinvestigation of the original x‐ray data, but no definitive evidence for the alternative space group could be obtained. An examination of a bulk sample of cis‐ [PtCl~2~(PPh~2~^n^Pr)(BzS{O}Bz)] by x‐ray powder diffraction and comparison of the results with data from the single‐crystal x‐ray diffraction experiment revealed that the crystal selected for diffraction studies was a different polymorph from the bulk of the sample which was used for the ^31^P CP/MAS NMR measurements. X‐ray powder diffraction is thus shown to provide a valuable bridge between solid‐state CP/MAS NMR measurements and single‐crystal x‐ray diffraction data.