New chelate complexes of trivalent y and lanthanides (Eu, Ho, Yb) with a triazene N-oxide: Synthesis, structural characterization and luminescence properties

摘要

Deprotonated 3-(4-nitrophenyl)-1-phenyltriazene N-oxide reacts with YCl_3·6H_2O and LnCl_3·6H _2O (Ln = Eu, Ho, Yb) to give the monoclinic chelate complexes [Y{O_2N(C_6H_4)NNN(O)Ph}_4](Et _3NH)·H_2O (1) (Ph = C_6H_5; Et = C_2H_5) and [Ln~(III){O_2N(C _6H_4)NNN(O)Ph}_4](Et_3NH)·H _2O·{CH_3OH} {Ln~(III) = Eu (2), Ho (3), Yb (4), in which the metal centers present a square antiprismatic configuration. As already observed for hydrated ammonium complexes of triazene-oxides ligands with (C_6H_4)-NO_2 groups, multiple, effective O···H and N···H interactions hold the species in supramolecular 3D assemblies. The optical and the luminescent properties of the triazene-oxide europium complex 2 are also presented and fully discussed.