Synthesis, crystal structures, and antibacterial activities of two copper(II) complexes derived from 1-[(2-morpholin-4-ylethylimino)methyl]-naphthalen-2-ol

Abstract

A trinuclear complex, [Cu(Cu(l-Br) 2 L) 2 ], and a dinuclear complex, [Cu 2 (l-Cl) 2 L 2 ], have been synthesized with the tridentate Schiff base 1-[(2-morpholin-4-ylethylimino)methyl]-naphthalen-2-ol (HL), derived from 2-hydroxy-1-naphthyaldehyde and 4-(2-aminoethyl)morpholine. Both complexes have been characterized by physicochemical and spectroscopic methods. [Cu(Cu(l-Br) 2 L) 2 ] is a centrosymmetric bromide and phenolate oxygen-bridged trinuclear compound, while complex [Cu 2 (l-Cl) 2 L 2 ] is a centrosymmetric-chloride-bridged dinuclear compound. The central Cu(II) atom in [Cu(Cu(l-Br) 2 L) 2 ] is six-coordinated in an octahedral coordination, while other Cu(II) atoms in both complexes are five-coordinated in squarepyramidal coordinations. Both complexes and HL were tested in vitro for their antibacterial activities.

Auxiliary Part of Ligand Mediated Unique Coordination Chemistry of Copper (II)

“…In addition a long Cu(1)-Br(2) bond of 2.8540(14) is measured for the apical site. The monovalent copper ion is tetrahedrally coordinated with Cu(2)-Br bond lengths ranging from 2.4263(14) to 2.5503 (15) , forming a [Cu 2 Br 6 ] 4 À anion, located on a crystallographic center of symmetry. It is worth of note that the phenolato ring was brominated in ortho position and the structural analysis indicate the presence of a disordered situation where bromine Br(5) has occupancy of ca.…”

“…A similar complex using 2-naphthol instead of 5-Cl-phenol has been reported a few years ago where the CuÀCu distance of 2.963 (2) , is comparable to that found in 5 A and slightly shorter than values measured in 5B and 6 ( Table 2). [15] IR and UV/Vis spectra of complexes.…”