Showing papers by "University of Lorraine published in 1988"
TL;DR: In this paper, des resultats de comparaison et dunicite for the solutions of problemes aux valeurs limites quasilineaires paraboliques avec (et sans) obstacles are presented.
Abstract: On presente des resultats de comparaison et d'unicite pour les solutions de problemes aux valeurs limites quasilineaires paraboliques avec (et sans) obstacles. Un resultat de stabilite dans L 1 (Ω) donne la stabilisation asymptotique dans cet espace, quand t→∞, vers le probleme elliptique correspondant
23 citations
TL;DR: The difluorogermanium(IV) porphyrins [GeF2(P)][P = 2,3,7,8,12,13,17,18-octaethyl porphyrinate(2-oep), 5,10,15,20-tetraphenylporphyrin(2−)(tpp), or 5, 10, 15,20tetra-p-tolylporphrin(2)-)(tptp)] have been prepared by reacting hydrogen fluoride with the appropriate
Abstract: The difluorogermanium(IV) porphyrins [GeF2(P)][P = 2,3,7,8,12,13,17,18-octaethylporphyrinate(2–)(oep), 5,10,15,20-tetraphenylporphyrinate(2–)(tpp), or 5,10,15,20-tetra-p-tolylporphyrinate(2–)(tptp)] have been prepared by reacting hydrogen fluoride with the appropriate dichloro derivative [GeCl2(P)]. The complexes were characterized by elemental analysis, 1H n.m.r., i.r., and u.v.–visible spectroscopy. The electrochemical behaviour was investigated in non-aqueous media while spectroelectrochemistry and e.s.r. were used to characterize the oxidized and reduced complexes. Each complex could be reversibly oxidized or reduced by one electron. In each case these electron additions or abstractions were ring centred. The crystal structure [GeF2(oep)] was determined by X-ray diffraction methods. The complex crystallizes in the space group I41/a, with a=b= 15.202(2), c= 13.910(3)A, and R= 0.034 and R′= 0.035 for 1 465 unique reflections. The germanium atom lies on a crystallographic axis and is co-ordinated by the porphyrin ring and two fluorine atoms; the short germanium–fluorine distance [1.790(2)A] is very close to that found in [FeF(tpp)][1.792(2)A].
10 citations
1 citations
TL;DR: The difluorogermanium(IV) porphyrins [GeF2(P)][P = 2,3,7,8,12,13,17,18-octaethyl porphyrinate(2-oep), 5,10,15,20-tetraphenylporphyrin(2−)(tpp), or 5, 10, 15,20tetra-p-tolylporphrin(2)-)(tptp)] have been prepared by reacting hydrogen fluoride with the appropriate
Abstract: The difluorogermanium(IV) porphyrins [GeF2(P)][P = 2,3,7,8,12,13,17,18-octaethylporphyrinate(2–)(oep), 5,10,15,20-tetraphenylporphyrinate(2–)(tpp), or 5,10,15,20-tetra-p-tolylporphyrinate(2–)(tptp)] have been prepared by reacting hydrogen fluoride with the appropriate dichloro derivative [GeCl2(P)]. The complexes were characterized by elemental analysis, 1H n.m.r., i.r., and u.v.–visible spectroscopy. The electrochemical behaviour was investigated in non-aqueous media while spectroelectrochemistry and e.s.r. were used to characterize the oxidized and reduced complexes. Each complex could be reversibly oxidized or reduced by one electron. In each case these electron additions or abstractions were ring centred. The crystal structure [GeF2(oep)] was determined by X-ray diffraction methods. The complex crystallizes in the space group I41/a, with a=b= 15.202(2), c= 13.910(3)A, and R= 0.034 and R′= 0.035 for 1 465 unique reflections. The germanium atom lies on a crystallographic axis and is co-ordinated by the porphyrin ring and two fluorine atoms; the short germanium–fluorine distance [1.790(2)A] is very close to that found in [FeF(tpp)][1.792(2)A].