Synthesis And Properties Of Functionalized Nitronyl Nitroxide Radical-Metal Complexes

The functionalized nitronyl nitroxide radicals complexes formed by metal ions and Ullman-type nitronyl nitroxide radicals are a research hot spot in magnetic materials.In recent decades,scientists have obtained many molecular-based magnetic materials by changing the coordination mode and coordination ability of nitronyl nitroxide radicals.In this paper,five functionalized nitronyl nitroxide radicals ligands and six metal ion-functionalized nitronyl nitroxide radical complexes were designed and synthesized to analyze the crystal structure of nitronyl nitroxide radicals and their complexes,and characterized by X-ray powder diffraction infrared,ultraviolet,thermogravimetric,etc.The magnetic properties of some complexes were analyzed.The main research contents are as follows:1.The five functionalized nitronyl nitroxide radicals have been synthesized.They are namely p-pyridylp-hydroxyphenyl nitronyl nitroxide(NIT-p-Py-p-PhO=2-[4-(4-pyridinylmethoxy)phenyl]-4,4,5,5-tetramethylimidazoline1-oxyl-3-oxide),m-pyridine-p-hydroxyphenyl nitronyl nitroxide(NIT-m-Py-p-PhO=2-[4-(3-pyridinyl-methoxy)phenyl]-4,4,5,5-tetramethylimidazolin e-1-oxyl-3-oxide),o-quinoxalinyl imino nitroxide(IM-o-QN=2-quinoxalinyl-4,4,5,5-tetramethylimidazoline-3-oxide),8-hydroxyquinolinyl nitronyl nitroxide(NITQ-8-OH=2-[(8-hydroxyl)quinolinyl]-4,4,5,5-tetramethylimidazoline-l-oxyl-3-ox ide),p-pyridyl nitronyl nitroxide(NIT-p-Py=2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide),respectively.2.Using copper hexafluoroacetylacetonate dihydrate[Cu(hfac)2·2H42O](hfac=hexafluoroacetylacetone)and four functionalized nitronyl nitroxide radicals(NIT-p-Py-p-PhO,NIT-m-Py-p-PhO,NITQ-8-OH,NIT-p-Py)as raw materiales,four functionalized nitronyl nitroxide radicals-copper complexes were synthesized:(a)the dimer ring complex {[Cu(hfac)2]2(NIT-p-Py-p-PhO)2}2;(b)Cu(hfac)2(NIT-m-Py-p-PhO)2;(c)[Cu(hfac)(NITQ-8-O)]2;(d)a 1D complex[Cu(hfac)2NITpPy]n.The magnetic interactions of complexes(b)and(d)have been studied.The analysis of the results shows that the complex(b)Cu(hfac)2(NIT-m-Py-p-PhO)2 has a ferromagnetic and antiferromagnetic interaction;the complex(d)[Cu(hfac)2NITpPy]n has an antiferromagnetic interaction between Cu(?)and N of the pyridyl on the nitronyl nitroxide;whereas there is a ferromagnetic interaction in the axial coordination between Cu(?)and the radical ONCNO group.3.Based on o-quinoxalinyl nitroxide radical(IM-o-QN),two complexes were synthesized with hexafluoroacetylacetone as the co-ligand:Zn(hfac)2(IM-o-QN),Ni(hfac)2(IM-o-QN).The magnetic interactions of complex Zn(hfac)2(IM-o-QN)has been studied.