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

نویسندگان

  • Maria G. F. Vaz
  • Marcelo Knobel
  • Nivaldo L. Speziali
  • Alexandre M. Moreira
  • Antônio F. C. Alcântara
چکیده

Neste trabalho, descrevemos a obtenção de dois novos compostos de cobre(II), ou precursores, (Pr-Rad) 2 [Cu(opba)].H 2 O (1) e (Bu-Rad) 2 [Cu(opba)].2H 2 O (2), onde opba é o ligante ortofenilenobis(oxamato) e R-Rad são radicais cátions do tipo nitronil nitróxido. A partir destes compostos 1 e 2, foram sintetizados os dois novos magnetos moleculares [Pr-Rad] 2 [Mn 2 {Cu(opba)} 3 ].3,3 DMSO.5H 2 O (3) e [Bu-Rad] 2 [Mn 2 {Cu(opba)} 3 ].3DMSO.6H 2 O (4), respectivamente. As propriedades magnéticas dos precursores 1 e 2 mostram a presença de interações ferromagnéticas entre os radicais cátions e o cobre (II), na faixa de temperatura entre 20 e 300 K. Os magnetos moleculares 3 e 4 exibem magnetização espontânea com temperatura crítica, T c , de 23 K e 24 K, respectivamente.

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تاریخ انتشار 2002