The CX3(+) salts [CCl(3)](+)[Al(OR(F))(4)](-)1, [CCl(3)](+)[(R(F)O)(3)Al-F-Al(OR(F))(3)](-)2, [CBr(3)](+)[Al(OR(F))(4)](-)3, [CBr(3)](+)[(R(F)O)(3)Al-F-Al(OR(F))(3)](-)4 (R(F) = C(CF(3))(3)) were prepared in 56 to 85% yield from CX(4) (X = Cl, Br) and the corresponding silver salts (weight balance, NMR, IR, X-ray structure of 1). The most convenient solvent for the preparation of 1 and 2 is SO(2)ClF but for 3 and 4 it is SO(2). The reactions are complete after about three days stirring at -30 to -40 °C. The salts are stable for weeks in solution at -40 °C and stable for a few hours at RT in the solid state. In SO(2)ClF (1, 2) or SO(2) (3, 4) solution they decompose slowly at -20 °C and within several hours at RT; in general the CBr3(+) salts are more stable than the CCl3(+) homologues. The decomposition products were assigned as CCl(3)F and primarily CBr(2)F(2) (which likely forms as a Lewis acid induced disproportionation product of the initial CBr(3)F). The C-X vibrations of the salts were found in the expected range and the assignments were made based on experimental and calculated data. The IR spectrum of a CBr3(+) salt is for the first time reported here.
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http://dx.doi.org/10.1039/c0dt01076f | DOI Listing |
Dalton Trans
February 2011
Albert-Ludwigs-Universität Freiburg, Institut für Anorganische und Analytische Chemie and Freiburger Materialforschungszentrum FMF, Freiburg, Germany.
J Am Chem Soc
May 2004
Department of Chemistry, McMaster University, Hamilton, Ontario, L8S 4M1, Canada.
The CCl(3)(+) and CBr(3)(+) cations have been synthesized by oxidation of a halide ligand of CCl(4) and CBr(4) at -78 degrees C in SO(2)ClF solvent by use of [XeOTeF(5)][Sb(OTeF(5))(6)]. The CBr(3)(+) cation reacts further with BrOTeF(5) to give CBr(OTeF(5))(2)(+), C(OTeF(5))(3)(+), and Br(2). The [XeOTeF(5)][Sb(OTeF(5))(6)] salt was also found to react with BrOTeF(5) in SO(2)ClF solvent at -78 degrees C to give the Br(OTeF(5))(2)(+) cation.
View Article and Find Full Text PDFBiochem J
May 2003
Division of Cell Signalling, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, Scotland, UK.
We investigated the kinetic behaviour and substrate specificity of PTEN (phosphatase and tensin homologue deleted on chromosome 10) using unilamellar vesicles containing substrate lipids in a background of phosphatidylcholine. PTEN displays the characteristics expected of an interfacial enzyme, since the rate of enzyme activity is dependent on the surface concentration of the substrate lipids used (mol fraction), as well as the bulk concentration. Surface-dilution analysis revealed the catalytic efficiency of PTEN for PtdIns(3,4,5) P (3) to be 200-fold greater than for either PtdIns(3,4) P (2) or PtdIns(3,5) P (2), and 1000-fold greater than for PtdIns3 P.
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