Three Novel Cyclic Zn(II)-Nitronyl Nitroxide Radical Complexes: Synthesis, Crystal Structures, and Properties

Using two flexible and functional nitronyl nitroxide radicals as ligands, three novel complexes [Zn(hfac)(2)(NIToPh3Py)](2) (1), [Zn(hfac)(2)(NITmPh3Py)](2) (2), and {[Zn(hfac)(2)](3)[(NITmPh3Py)](2)}(n) (3) (where NIToPh3Py is 2-[2-methoxyphenyl(3-pyridinyl)]-4,4,5,5 -tetramethyl-imidazoline1-oxyl-3-oxide; NITmPh3Py is 2-[3-methoxyphenyl(3-pyridinyl)]-4,4,5,5-tetramethyl-imidazoline1-oxyl-3-oxide; hfac is hexafluoroacetylacetonate) have been obtained by the reactions of Zn(hfac)(2)center dot H2O with NIToPh3Py/NITmPh3Py in n-heptane upon adjusting the experimental conditions. Their crystal structures and magnetic properties have been studied. X-ray crystal diffraction studies have revealed that complexes 1 and 2 display binuclear cyclic structure, while 3 presents a ring-chain polymer consisting of cyclic [Zn-Radical](2) dimers connected by Zn(hfac)(2) units. The magnetic behaviors of the complexes 1-3 have been investigated and discussed in connection with their crystal structures.