An Unexpected Salamo-Type Copper(II) Complex: Synthesis, Crystal Structure, Thermal Behavior, and Spectroscopic Analysis

A novel supramolecular Cu(ΙΙ) complex [Cu2(L2)2] (H2L2 = 4-bromosalicylaldehyde O-(2-hydroxyethyl)oxime) is synthesized through the complexation of Cu(OAc)2·H2O with an asymmetric salamo-type ligand 4-bromo-6′-hydroxy-2,2′-[ethylenedioxybis(nitrilomethylidyne)]diphenol (H3L1) and is structurally characterized by single crystal X-ray diffraction. The X-ray crystal structure of the Cu(ΙΙ) complex reveals it to crystallize in the triclinic system, space group $$P\overline1$$ , in which each Cu(II) atom is in a distorted square pyramidal geometry. The whole Cu(ΙΙ) complex consists of a series of [Cu2(L2)2] units, forming an infinite 1D chain supramolecular structure. Meanwhile, the Cu(II) complex exhibits emission with the maximum emission wavelength λmax = 431 nm when excited at λex = 367 nm.