Crystal structures and magnetic properties of manganese and cobalt binuclear complexes based on nitroxide radical

Two analogous binuclear coordination complexes derived from nitronyl nitroxide radical ligands have been synthesized. Their general formulae are [Mn-2(hfac)(4)(NIT-mo-pmy)(2)] (1) and [Co-2(hfac)(4)(NIT-mo-pmy)(2)] (2), respectively, where hfac= hexafluoroacetylacetone and NIT-mo-pmy=2-(2-methoxy-5'-pyrimidinyl) 4,4,5,5-tetra-methyl-imidazoline-3-oxy-1-oxyl radical. Both complexes crystallize in a triclinic system P (1) over bar space group, exhibiting a centrosymmetric rectangle-like array based on dimer coordination units. Variable-temperature magnetic characterizations reveal the presence of antiferromagnetic exchanges between central ions and nitroxide radicals in both four-spin nitroxide radical complexes. The different strengths of both complexes were investigated based on structure-property relationship analysis. The magnetic behaviors of the Mn.. complex have been quantitatively evaluated through an appropriate magnetic model and were compared with the relevant complexes. CCDC: 2094992, 1; 2094993, 2.