Synthesis and Properties of New Molecule-Based Magnets Containing Mn(II), Cu(II) and Nitronyl Nitroxide Radical Cation

• Autor(a) principal: Vaz,Maria G. F.
• Data de Publicação: 2002
• Outros Autores: Knobel,Marcelo, Speziali,Nivaldo L., Moreira,Alexandre M., Alcântara,Antônio F. C., Stumpf,Humberto O.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532002000200009
• topic: supramolecular chemistry; molecule-based magnets; molecular materials; catenanes; ferrimagnetism

In this work, we describe the synthesis of two new copper(II) compounds, (Pr-Rad)2 [Cu(opba)].H2O (1) and (Bu-Rad)2[Cu(opba)].2H2O (2) where opba stands for ortho-phenylenebis(oxamato) and RRad+ are nitronyl nitroxide radical cations. From 1 and 2, two new molecule-based magnets [Pr-Rad]2[Mn2{Cu(opba)}3 ].3.3DMSO.5H2O (3) and [Bu-Rad]2 [Mn2{Cu(opba)}3].3DMSO.6H 2O (4) were obtained, respectively. The magnetic properties of precursors 1 and 2 show the presence of ferromagnetic interaction between the radical cations with copper(II), in the temperature range of 20-300 K. The magnets 3 and 4 exhibit spontaneous magnetization at critical temperatures, Tc, of 23 K and 24 K, respectively.