Abstract
We report the preparations, crystal structures and magnetic properties of three complexes formed by triMeO-NN = 2-{3,4,5-trimethoxyphenyl}-4,4,5,5- tetramethylimdazoline-1-oxyl-3-oxide) and MII(hfac)2 (MII = MnII, CoII, NiII and CuII) under inert atmosphere and anhydrous conditions. The X-ray structural analyses revealed that the fomulae of those complexes to be [(triMeO-NN)MnII(hfac)2]n (1), [(triMeO-NN)2MnII(hfac)2][MnII(hfac)2(H2O)2] (2), and [(triMeO-NN)2MnII(hfac)2] (solvent)2 (3). Interestingly, 1 and 2 have chain structure that is chiral for the former but achiral and hydrogen-bonded through NN and H2O for the latter. The structures of two spontaneously resolved enantiomers, space group P61 or P65, of 1 have been determined. 3 is a monomer.
1 is a soft ferrimagnet (TC = 4.6 K) with a strong AF NN-Mn exchange coupling. In contrast, 2 display strong AF coupling for the NN-Mn and weak ferromagnetic NN-H2O-Mn coupling. No long-range magnetic ordering is observed. 3 behaves as a paramagnet with strong AF coupling between NN and Mn.
