Synthesis, structures and properties of cobalt(II) and copper(I) complexes of 2,6-diamino-3-[(2-carboxymethyl)phenylazo]-pyridine

Abstract The reaction of methyl anthranilate, sodium nitrite, and 2,6-diamino-pyridine affords a new compound, 2,6-diamino-3-[(2-carboxymethyl) phenylazo]-pyridine (L), which has been characterized with X-ray crystallography and NMR spectrum. The reaction of L and CoCl 2 ⋅ 6H 2 O or Cu(ClO 4 ) 2 ⋅ 6H 2 O gives a dinuclear cobalt(II) complex [Co 2 L 2 Cl 3 ]Cl ( 1 ), and a copper(I) complex [CuL 2 ]ClO 4 ( 2 )，respectively. They are characterized by X-ray crystallography, X-ray photoelectron spectroscopy, NMR spectra, magnetic measurement and emission spectra. Magnetic behavior of 1 denotes the occurrence of intramolecular antiferromagnetic interactions (J = − 141.8 cm − 1 ) . Complex 2 exhibits photoluminescence at 557 nm.