Co(II), Ni(II) and Cu(II) complexes of new [1+1] and [2+2] macrocyclic ligands derived from 1,4-bis(2′-formylphenyl)-1,4-dioxabutane and cis-1,2-diaminocyclohexane

Two new macrocyclic ligands, L1(14-membered, N2O2) and L2(28-membered, N4O4) from [1+1] and [2+2] condensation, respectively, have been obtained in a one-pot synthesis starting from 1,4-bis(2′-formylphenyl)-1,4-dioxabutane and cis-1,2-diaminocyclohexane, in satisfactory yield and purity. Metal complexes of L2using hydrated nitrate and perchlorate salts of transitional Co(II), Ni(II) and Cu(II) metal ions have been synthesized and characterized by microanalysis, LSI-MS, IR and UV-Vis spectroscopy, magnetic measurements and conductivity measurements. Crystal structures of L1 and the mononuclear [Co(HL2)(NO3)2(CH3CN)](NO3) · 2CH3CN, [NiL2(NO3)](NO3) · 2H2O · CH3CN and the dinuclear [Cu2L2(NO3)4].4CH3CN complexes have been determined by X-ray diffraction.