A unique 2-D hollow sheet structure and magnetic behavior of a cyanide- and triamine-bridged MnIICrIII ferrimagnet

A 2-D cyanide- and triamine-bridged MnIICrIII ferrimagnet, [Mn3(dien)2(H2O)2][Cr(CN)6]2 · 4H2O (1), has been prepared by the combination of Mn2+, diethylenetriamine (dien) co-ligand and [Cr(CN)6]3−. This compound forms a unique 2-D hollow sheet structure constructed by 1-D ribbon networks on the basis of triamine (dien)-bridged trinuclear MnII units. Compound 1 readily looses all lattice water molecules and irreversibly changes to a dehydrated form, [Mn3(dien)2(H2O)2][Cr(CN)6]2 (1a), in the air. Cryomagnetic studies of 1 and 1a reveal an antiferromagnetic interaction between CrIII and MnII ions, and an unusual long-range ferrimagnetic ordering below 30 K (1) and 40 K (1a) with multiple magnetic phase changes below TC. MCD spectra of 1a show a strong Faraday ellipticity associated with the LMCT band of the Cr–CN below 300 nm. Faraday ellipticity is remarkably enhanced below TC in line with the characteristics long-range ferrimagnetic ordering.

A two-dimensional cyanide- and triamine-bridged MnIICrIII ferrimagnet, [Mn3(dien)2(H2O)2][Cr(CN)6]2 · 4H2O, has been prepared and characterized its structural and magnetic changes associated with dehydration. This compound irreversibly changed to a dehydrated form and the hydrated and the dehydrated forms show an unusual long-range ferrimagnetic ordering with multiple magnetic phase changes reflecting a unique 2-D hollow sheet structure.Figure optionsDownload as PowerPoint slide