ISSN:
0009-2940
Keywords:
Fluorophosphoranes
;
Donor-acceptor interaction
;
Azonium salts
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The reaction of the tetrafluorophosphoranes RPF4 [R = CH3, C6H5, C6F5, (CH3)3SiCH2, and 2,5-(CH3)2C6H3] with N,N,Ń-trimethyl-N′-(trimethylsilyl))ethylenediamine (1) yields the corresponding triflurophosphoranes 2-6 by cleavage of the Si - N bond and elimination of (CH3)3SiF. In an analogous reaction the difluorophosphoranes R1R2PF2N(CH3)CH2CJ2N-(CH3)2 (R1 = R2 = C6H5, 7: R1 = C6H5, R2 = C4H4N, 8) are formed. Some of these N,N,Ń-trimethylethylenediamine-substituted di- and trifluorophosphoranes react with PF5 as a Lewis acid to form the corresponding azonium hexafluorophosphates 9-12 as a result of fluoride abstraction and intramolecular (CH3)2N→P donor-acceptor interaction. Compound 13 shows dynamic behaviour in solution. An exchange process is observed for the axial and equatorial fluorine atoms by 19F- and 31P-NMR spectroscopy. An X-ray structure analysis of the compounds 10 - 12 reveals the expected trigonal-bipyramidal geometry at phosphorus. The ethylenediamine ligand is found to form a chelate ring, whereby one axial and one equatorial site are bridged. The coordinative P - N bonds are very long (up to 207 pm).
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19911240605
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