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Binuclear complexes with general formula [Ln(hfac)(HO)(dppnTEMPO)] (Ln = Gd, Tb, and Dy) have been obtained using the paramagnetic ligand 1-piperidinyl-4-[(diphenylphosphinyl)amino]-2,2,6,6-tetramethyl (dppnTEMPO) as a bridge. One of the lanthanide ions is ferromagnetically coupled with the TEMPO moiety. Two of the complexes (Dy and Tb) show slow relaxation of the magnetization, and the non-magneto-equivalence of the two Ln ions was clearly observed. The ab initio CASSCF calculations were employed to confirm this behavior, as well as to rationalize the Ln-Rad interaction. The simulations of the magnetic properties were allowed by the insights given by the calculations. The inequivalence of the Tb ions was also proved by emission spectroscopy.

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Organo-phosphorus compoundsOrgano-phosphorus compounds S 0080 Dilithiated Phosphazenes: Scaffolds for the Synthesis of Olefins Through a New Class of Bicyclic 1,2-Oxaphosphetanes. -The dianions derived from phosphazenes (I) react with carbonyl compounds (II) to yield spirocyclic 1,2-oxaphosphetanes (III), which furnish quantitatively substituted olefins [cf. (IV)] through stereospecific thermolysis. -(GARCIA-LOPEZ, J.; PERALTA-PEREZ, E.; FORCEN-ACEBAL, A.; GARCIA-GRANDA, S.; LOPEZ-ORTIZ*, F.; Chem. Commun. (Cambridge) 2003, 7, 856-857; Area Quim. Org., Univ. Almeria, E-04120 Almeria, Spain; Eng.) -M. Schroeter 30-199