Bimetallic 3d—4f-molecules [MEu(ButCOO)5(1,10-phen)] (M = Zn2+, Co2+, phen is phenanthroline): synthesis, structure, luminescent and magnetic properties

Abstract

New heterometallic complexes [MEu(Piv)₅(1,10-phen)]•MeCN (M = Zn²⁺ (1), Co²⁺ (2), Piv^– = Bu^tCOO^–, 1,10-phen is 1,10-phenanthroline) were obtained. Luminescence spectra of compound 1 reveal a metal-centered Eu³⁺ luminescence, the luminescence lifetime is about 1 ms. Using TGA and DSC methods, it was shown that [ZnEu(Piv)₅(1,10-phen)] is a stable binuclear molecule undergoing a structural transformation in the 210—230 °C temperature range, which leads to a partial transition of the sample into the glass state. Complex 2 does not exhibit luminescence due to the presence of high-spin cobalt(II) ions. The magnetic behavior of 2 according to calculations based on the molecular field model is determined by spin-orbit interactions of cobalt(II) and europium(III) ions.