Study of the Luminescent and Magnetic Properties of a Series of Heterodinuclear [ZnIILnIII] Complexes

Herein, we report the synthesis, structural investigation, and magnetic and photophysical properties of a series of 13 [Zn(II)Ln(III)] heterodinuclear complexes, which have been obtained employing a Schiff-base compartmental ligand derived from o-vanillin [H(2)valpn = 1,3-propanediylbis(2-iminomethylene-6-methoxy-phenol)]. The complexes have been synthesized starting from the [Zn(valpn)(H2O)] mononuclear compound and the corresponding lanthanide nitrates. The crystallographic investigation indicated two structural types: the first one, [Zn(H2O)(valpn)Ln(III)(O2NO)(3)], contains 10-coordinated Ln(III) ions, while in the second one, [Zn(ONO2)(valpn)Ln(III)(H2O)(O2NO)(2)] center dot 2H(2)O, the rare earth ions are nine-coordinated. The Zn-II ions always display a square-pyramidal geometry. The first structural type encompasses the larger Ln ions (4f(0)-4f(9)), while the second is found for the smaller ions (4f(8)-4f(11)). The dyskrosium derivative crystallizes in both forms. Luminescence studies for the heterodinuclear compounds containing Nd-III, Sm-III, Tb-III, Dy-III, and Yb-III revealed that the [Zn(valpn)(H2O)] moiety acts as an antenna. The magnetic properties for the paramagnetic [Zn(II)Ln(III)] complexes have been investigated.