Homo- and hetero-binuclear complexes of new binucleating ligand N,N′-bis(3-methoxycarbonylsalicylidene)ethylenediamine

Abstract

Dicopper(II), copper(II)nickel(II), and copper(II)cobalt(II) complexes of the general formula [CuM(L)X 2] (X = halogeno ion) have been synthesized using N,N′-bis(3-methoxycarbonylsalicylidene)ethylenediamine (H 2L). Based on infrared and electronic spectra, it is shown that the copper(II) ion is bound at the N 2O 2-site with the imino nitrogens and the bridging phenolic oxygens and the second metal ion (M(II)) is bound at the O 4-site with the bridging phenolic oxygens and the carbonyl oxygens of the ester groups. In the case of [CuNi(L)X 2] and [CuCo(L)X 2], the configuration around the second metal is pseudo-octahedral with halogeno ions at the apical sites. Cryomagnetic investigations reveal the operation of an antiferromagnetic spin-exchange interaction between the copper(II) and M(II) ions for all the complexes.