Stabilization of substituted triazene oxides by lanthanides chelation: Synthesis, TGA evaluations and X-ray structural features of [MIII{O2NPhNNN(O)Ph}4](Et3NH)·H2O (M = La3+, Dy3+; Et = C2H5)

Deprotonated 3-(4-nitrophenyl)-1-phenyltriazene N-oxide reacts with La(NO3)3·6H2O and DyCl3 · 6H2O to give [MIII{O2NPhNNN(O)Ph}4](Et3NH)·H2O (M = La3+ (1), Dy3+ (2); Et = C2H5). In both complexes the metal centers present the coordination number 8, with a square antiprismatic configuration. As already expected for triazene oxides with PhNO2 groups, multiple, effective O···H interactions hold the species in two-dimensional layers in the bc plane. TGA and IR data of both compounds are also presented and discussed.