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Titolo:
Chelated fluoroboron cations. I. Synthesis and NMR studies involving the tertiary-amine ligands N,N,N ',N '-tetramethylethylenediamine and N,N,N ',N '',N ''-pentamethyldiethylenetriamine
Autore:
Shoemaker, JAW; Hartman, JS;
Indirizzi:
Brock Univ, Dept Chem, St Catharines, ON L2S 3A1, Canada Brock Univ St Catharines ON Canada L2S 3A1 Catharines, ON L2S 3A1, Canada
Titolo Testata:
CANADIAN JOURNAL OF CHEMISTRY-REVUE CANADIENNE DE CHIMIE
fascicolo: 11, volume: 77, anno: 1999,
pagine: 1856 - 1868
SICI:
0008-4042(199911)77:11<1856:CFCISA>2.0.ZU;2-X
Fonte:
ISI
Lingua:
ENG
Soggetto:
MOLECULAR ADDITION-COMPOUNDS; BORON-TRIFLUORIDE; REACTION-MECHANISMS; DYNAMIC BEHAVIOR; SPECTROSCOPY; FLUOROPOLYMERS; FLUORESCENCE; RESONANCE; COMPLEX;
Keywords:
N,N,N ',N '-tetramethylethylenediamine; N,N,N ',N '',N ''-pentamethyldiethylenetriamine; chelated fluoroboron cations; fluorine-19 NMR; boron-11 NMR; pyridine; isoxazole; chiral; magnetically nonequivalent;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
43
Recensione:
Indirizzi per estratti:
Indirizzo: Hartman, JS Brock Univ, Dept Chem, St Catharines, ON L2S 3A1, Canada BrockUniv St Catharines ON Canada L2S 3A1 ON L2S 3A1, Canada
Citazione:
J.A.W. Shoemaker e J.S. Hartman, "Chelated fluoroboron cations. I. Synthesis and NMR studies involving the tertiary-amine ligands N,N,N ',N '-tetramethylethylenediamine and N,N,N ',N '',N ''-pentamethyldiethylenetriamine", CAN J CHEM, 77(11), 1999, pp. 1856-1868

Abstract

Several possible methods of synthesis of chelated fluoroboron cations are explored, using the tert-amines N,N',N,N'-tetramethylethylenediamine (Me(4)en) and N,N,N',N",N"-pentamethyldiethylenetriamine (Me(5)dien) as model chelating ligands. Both ligands displace pyridine from (pyr)(2)BF2+ (as its PF6- salt) to form the bidentate (Me(4)en)BF2+ and (Me(5)dien)BF2+ cations. The same cations, as well as the corresponding BFCl+ and BFBr+ cations, can also be prepared by displacement of the donor molecule (D = pyridine or isoxazole) and the heavy halide ion (Cl- or Br) from the neutral D.BF2X and D.BFX2 adducts. The central nitrogen of Me(5)dien becomes chiral when it and one terminal nitrogen are coordinated, and the prochiral and magnetically nonequivalent fluorines of (Me(5)dien)BF2+ give F-19 NMR signals separated by 1.2 ppm. In (Me(5)dien)BFCl+ the boron is a second chiral centre and the two diastereomers, distinguishable by NMR with F-19 chemical shifts differing by 3.0 ppm, form in a 3:1 ratio. The bidentate BFBr+ cations of Me(4)en and Me(5)dien are insoluble in non-coordinating solvents but have been detected by positive ion FAB mass spectrometry and B-11 MAS NMR. The tridentatecomplex (Me(5)dien)BF+2 does not form under our conditions.

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Documento generato il 26/09/20 alle ore 05:45:28