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Title: Phosphoranimines containing cationic N-imidazolinium moieties

For this study, three new monomeric phosphoranimines (PAs; R'—N=PR 3) were synthesized by the Staudinger route using 2-azido-1,3-dimethylimidazolinium hexafluorophosphate [ADMImPF] and various phosphines to form their respective PA salts of triphenylphosphine (1), tri(n-octyl)phosphine (2), and tris(2,2,2-trifluoroethoxy)phosphite (3). These PA salts have a cationic imidazolinium moiety attached to nitrogen. Interestingly, 2 is a room temperature ionic liquid (RTIL) with a melting point around -5°C and a viscosity of 740cP at 25.5°C. 1 and 2 show stability to moisture exposure and atmosphere for weeks whereas 3 is not stable toward atmospheric moisture undergoing decomposition to form 2-amino-1,3-dimethylimidazolinium phosphate (4). Thermal analyses reveal that 1 and 2 are stable to 90°C under nitrogen, but 3 undergoes degradation by exposure to moisture and/or elevated temperature. All compounds exhibit similar multinuclear NMR chemical shifts as compared to their corresponding phosphine oxide counterparts. However, their respective X-ray structure determinations indicate that 2 has an open structure with the octyl groups that avoid the ionic charges, whereas 1 and 3 have tighter structural packing of the hexafluorophosphate to their pendant groups.$$\longequal$$
ORCiD logo [1] ; ORCiD logo [1] ; ORCiD logo [1] ;  [2] ; ORCiD logo [3]
  1. Idaho National Lab. (INL), Idaho Falls, ID (United States). Biological and Chemical Processing
  2. Univ. of Wyoming, Laramie, WY (United States). Dept. of Chemistry
  3. Idaho National Lab. (INL), Idaho Falls, ID (United States). Energy Storage and Advanced Vehicles
Publication Date:
Report Number(s):
Journal ID: ISSN 0020-1693
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Inorganica Chimica Acta
Additional Journal Information:
Journal Volume: 466; Journal Issue: C; Journal ID: ISSN 0020-1693
Research Org:
Idaho National Lab. (INL), Idaho Falls, ID (United States)
Sponsoring Org:
USDOE Office of Nuclear Energy (NE); USDOE Laboratory Directed Research and Development (LDRD) Program
Country of Publication:
United States
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; phosphoranimine; Ionic compounds; characterization; NMR; X-ray crystal structure; synthesis; room temperature ionic liquid
OSTI Identifier: