   Synthesis of New Tetraethyl(N-alkyl-1-aminoethan-1,1-diyl)bisphosphonates and ESR Analysis of Chemical Exchange of Derived Nitroxides of Acyclic Aminobisphosphonates.Olive, Gilles  ; ; et alin Phosphorus, Sulfur & Silicon & the Related Elements (2007), 182(10), 2359-2369 The synthesis and the full characterization of two new linear bisphosphonates(tetraethyl(N-tert-butyl-1-aminoethan-1,1-diyl)bisphosphonate and tetraethyl(Nsec-butyl-1-aminoethan-1,1-diyl)bisphosphonate ... [more ▼] The synthesis and the full characterization of two new linear bisphosphonates(tetraethyl(N-tert-butyl-1-aminoethan-1,1-diyl)bisphosphonate and tetraethyl(Nsec-butyl-1-aminoethan-1,1-diyl)bisphosphonate), and the first analysis of the ESR spectra of the corresponding nitroxides is reported. The preliminary results of theoretical calculations on model compounds suggest a small B0 (in the McConnell equation). The results of bisphosphonate ester and bisphosphonic acid are similar. The discrepancies of P coupling for the diphosphorus compound stems from B2 that is different when the dihedral angle is larger than 90◦. [less ▲] Detailed reference viewed: 13 (0 ULg)ESR Investigation of Chemical Exchange in Geminally Diphosphorylated Linear Nitroxide Radicals; Olive, Gilles ; et alin Journal of Physical Chemistry A (2004), 108(25), 5484-5489 For geminally diphosphorylated linear nitroxide radicals, a marked line width alternation (LWA) can be observed. The LWA appears irrespectively whether the investigated radicals R¢¢N(O¥)C(P(O)(OEt)2)2R¢ ... [more ▼] For geminally diphosphorylated linear nitroxide radicals, a marked line width alternation (LWA) can be observed. The LWA appears irrespectively whether the investigated radicals R¢¢N(O¥)C(P(O)(OEt)2)2R¢ contain any chiral group or not. If R¢¢ ) tert-butyl and R¢ ) H, the small â-hydrogen coupling indicates a completely blocked rotation around the N-C ó-bond and the LWA can be assigned to a chemical exchange between conformations in which the phosphoryl groups have a symmetric and a nonsymmetric geometry. The conformational change is accompanied by the deformation of the CP2 bonding angle and the rate of exchange is slowed in pentane for which the solvent molecules can be trapped by the chelating phosphoryl groups. If R¢¢ ) benzyl, both the proton hyperfine lines of the CH2 group and the phosphorus lines of the CP2 group produce a LWA; two coalescences can be observed. In the case of a chiral R¢¢ group (R¢¢ ) secondary butyl, R¢ ) methyl) a tentative four-site model can explain the highly complex LWA. [less ▲] Detailed reference viewed: 7 (1 ULg)Optimization, continuation and lack of the one-step diphosphorylation reaction. Assay of modification of the tetraethyl(pyrrolidine-2,2-diyl)bisphosphonateOlive, Gilles ; in Phosphorus, Sulfur & Silicon & the Related Elements (2003), 178(1), 33-46 The optimization of the one-step diphosphorylation reaction is reported. The synthesis of new ®-aminobisphosphonates with four- and sixmembered rings and acyclic species with several substituents on the ... [more ▼] The optimization of the one-step diphosphorylation reaction is reported. The synthesis of new ®-aminobisphosphonates with four- and sixmembered rings and acyclic species with several substituents on the nitrogen atom and on the carbon atom bearing the two phosphorus atoms is described. [less ▲] Detailed reference viewed: 3 (0 ULg)Control of the Radical Polymerization by 2,2,15,15-tetramethyl-1-aza-4,7,10,13-tetraoxacyclopentadecan-1-oxyl and its Sodium SaltOlive, Gilles ; ; et alin Macromolecular Chemistry and Physics (2002), 203(12), 1790-1796 The control of the radical polymerization of styrene by 2,2,15,15-tetramethyl-1-aza-4,7,10,13-tetraoxacyclopentadecan-1-oxyl is reported here in bulk at 90 °C, 120 °C and in miniemulsion. Similarly, the ... [more ▼] The control of the radical polymerization of styrene by 2,2,15,15-tetramethyl-1-aza-4,7,10,13-tetraoxacyclopentadecan-1-oxyl is reported here in bulk at 90 °C, 120 °C and in miniemulsion. Similarly, the control by its sodium complex is reported in bulk at 90 °C. [less ▲] Detailed reference viewed: 4 (0 ULg) Tetraethyl(Pyrrolidine-2,2-diyl)BisphosphonateOlive, Gilles ; in Molecules (2001), 6 Detailed reference viewed: 5 (2 ULg) |
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