- Autor
- Scharfetter, Hermann
- Fischer, Roland
- Krassnig, Paul
- Thonhofer, Martin
- Theyer, Felix
- Gösweiner, Christian
- TitelTris(2-Methoxyphenyl)Bismuthine Polymorphism Characterized by Nuclear Quadrupole Resonance Spectroscopy
- Datei
- DOI10.3390/cryst9090446
- Persistent Identifier
- Erschienen inCrystals
- Band9
- Erscheinungsjahr2019
- Heft9
- Seiten446
- LicenceCC BY
- ISSN2073-4352
- Download Statistik1818
- Peer ReviewJa
- AbstractBased on the previous identification of metastable polymorphs in crystalline triphenylbismuth by nuclear quadrupole resonance spectroscopy (NQRS), the potential formation of similar phases was studied in Tris(2-Methoxyphenyl)Bismuthine. To this end, commercial samples with known NQRS properties were molten and re-crystallized at different speeds (shock freezing in different coolants versus slow cooling inside of a heater). In all recrystallization products we have identified a new crystal phase which has not been observed after synthesis from a solution. The new crystallographic structure has been confirmed by X-ray diffraction (XRD). The newly isolated polymorph crystallizes in the monoclinic space group P2(1)/c with only one molecule in the asymmetric unit and consequently only one 5/2-7/2 transition is observed at 88.75 MHz at 310 K. In contrast, the two transitions at 89.38 and 89.29 MHz for the well-known trigonal polymorph originate from two crystallographically distinct molecules of Tris(2-methoxy- Phenyl)Bismuthine in the asymmetric unit. Additional relaxometric NQRS shows distinctly different T 2 relaxation times for the new polymorph when compared to the original samples. Additional phase transitions could not be observed during temperature sweeps between 153K and 323K.
[708.31 KB]