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Bis-and tris (amidine) fluoroboron cations and related systems studies by Multinuclear NMR and fast atom bombardment mass spectometry

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dc.contributor.author Yuan, Cheng. en_US
dc.date.accessioned 2009-10-02T13:19:55Z
dc.date.available 2009-10-02T13:19:55Z
dc.date.issued 1988-10-02T13:19:55Z
dc.identifier.uri http://hdl.handle.net/10464/2743
dc.description.abstract The formation and the isolation of fluoroboron salts, (D2BF2+)(PF6-), (DD'BF2+)(PF6-) and (D3BF2+)(PF6-)2, have been carried out. 1,8-Diazabicyclo [5,4.0]undec-7-ene (DBU) and 1,5-diazabicyclo[4,3,O]non-5-ene (DBN), extremely strong organic bases, were introduced into the fluoroboron cation systems and induced a complicated redistribution reaction in the D/BF3/BC13 systems. The result was the formation of all BFnCI4-n-, D.BFnCI3-n and fluoroboron cation species which were detected by 19p and 11B NMR spectrometry. The displacement reaction of CI- from these D.BFnCI3-n (n = 1 and 2) species by the second entering ligand is much faster than in other nitrogen donor containing systems which have been previously studied. Tetramethylguanidine, oxazolines and thiazolines can also produce similar reactions in D/BF3/BCI3 systems, but no significant BFnC4-n- species were observed. As well as influences of their basicity and their steric hindrance, N=C-R(X) (X = N, 0 or S) and N=C( X)2 (X = N or S) structures of ligands have significant effects on the fonnationof fluoroboron cations and the related NMR parameters. D3BF2+ and some D2BF2+ show the expected inertness, but (DBU)2BF2+ shows an interestingly high reactivity. (D2BF2+)(X-) formed from weak organic bases such as pyridine can react with stronger organic bases and form DD'BF2+ and D'2BF2+ in acetone or nitromethane. Fast atom bombardment mass spectrometry is doubly meaningful to this work. Firstly, FABMS can be directly applied to the complicated fluoroboron cation containing solution systems as an excellent complementary technique to multinuclear NMR. Secondly, the gas-phase ion substitution reaction of (D2BF2+)(PF6-) with the strong organic bases is successfully observed in a FABMS ion source when the B-N bond is not too strong in these cations. en_US
dc.language.iso eng en_US
dc.publisher Brock University en_US
dc.subject Mass spectrometry. en_US
dc.subject Nuclear magnetic resonance. en_US
dc.subject Cations. en_US
dc.subject Amidines. en_US
dc.subject Boron. en_US
dc.title Bis-and tris (amidine) fluoroboron cations and related systems studies by Multinuclear NMR and fast atom bombardment mass spectometry en_US
dc.type Electronic Thesis or Dissertation en_US
dc.degree.name M.Sc. Chemistry en_US
dc.degree.level Masters en_US
dc.contributor.department Department of Chemistry en_US
dc.degree.discipline Faculty of Mathematics and Science en_US


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