Non-template synthesis and Characterization of 17-Membered Schiff Base Macrocycle Containing Oxygen and Nitrogen Heteroatoms and Its Metal Complexes

Abstract

A new ligand 1,7-bis(2´-formylphenyl)-4-benzyl-1,7-dioxa-4-azaheptane (L´) has been synthesized by the direct reaction of PhCH₂N(CH₂CH₂Cl)₂ with salicylaldehyde. The condensation of L´ with ethylenediamine in methanol gave a new type of oxa-aza Schiff base macrocycle 3,4:12,13-dibenzo-8-benzyl-1 ,8,15-triaza- 5,11- dioxacycloheptadeca-1,14-diene (L), and its complexes with Cu²⁺, Ni²⁺, Fe³⁺, Co²⁺, La³⁺, Pr³⁺, Nd³⁺, Sm³⁺, Gd³⁺ and UO²⁺₂ are synthesized and characterized by elemental analysis UV-Vis,IR, ¹H NMR and MS spectral techniques as well as molar conductance. An octahedral geometry around the metal ion is inferred for (ML)Xn (M=Cu²⁺, Ni²⁺, Fe³⁺ and Co²⁺; X=ClO^–₄, Cl^– or NO^–₃); n=2 or 3). The molar conductivity for all complexes suggests them to be 1 : 2 electrolytic nature. In the complexes, the metal ions are coordinated by N and O atoms of the ligand.