title: Bis[bis[5-tert-butyl-2-oxido-3-(1-pyridiniomethyl)phenyl]methane]dioxouranium bis(trifluoromethanesulfonate) pyridine disolvate: a uranyl bis(diphenoxide) complex resulting from homooxacalixarenecleavage.
abstract: The title compound, [UO(2)(C(33)H(38)N(2)O(2))(2)](CF(3)SO(3))(2).2C(5)H(5)N, has been obtained by reaction of U(IV) trifluoromethanesulfonate with p-tert-butyltetrahomodioxacalix[4]arene in pyridine. The uranyl ion lies on an inversion centre and is bound to two O atoms from each diphenoxide ligand, which gives the usual square-planar equatorial environment. The zwitterionic diphenoxide species results from nucleophilic attack by pyridine on the benzylic ether C atoms of the homooxacalixarene, assisted by initial U coordination to the ether groups, with subsequent metal oxidation giving the uranyl moiety.
authors.affiliation: CEA/Saclay, DSM/DRECAM/SCM, CNRS URA 331, Bâtiment 125, 91191 Gif-sur-Yvette, France.
authors.forename: Lionel
authors.initials: L
authors.lastname: Salmon
authors.forename: Pierre
authors.initials: P
authors.lastname: Thuéry
authors.forename: Michel
authors.initials: M
authors.lastname: Ephritikhine
authors.forename: Bernardo
authors.initials: B
authors.lastname: Masci