A chiral tetranuclear copper(II) complex based on a new Schiff-base ligand: Synthesis, structure, magnetic property and CD spectra

New chiral Schiff-base ligand l-H2vap, derived from the condensation of o-vanillin and l-2-amino-3-phenyl-1-propanol, reacts with Cu(Ac)2·H2O and Gd(NO3)3·6H2O in the presence of triethylamine to produce a chiral tetranuclear complex l-[Cu4(Hvap)2(vap)2(MeOH)2](NO3)2·MeOH (1). The single-crystal X-ray diffraction analyses reveal that complex 1 crystallizes in the chiral monoclinic space group P21 with Z = 2. Four copper(II) atoms are held together by two alkoxide μ3-O2 − atoms and two phenoxide μ2-O2 − atoms from four individual ligands to form a boat-shaped {Cu4O4} unit. The solid-state CD spectra confirm the chiral nature of complex 1. Magnetic studies indicate that there are strong antiferromagnetic interactions between the adjacent copper(II) ions in complex 1.