Synthesis and magnetic properties of one-dimensional ferro- and ferrimagnetic chains made up of an alternating array of 1,3-bis(N-tert-butyl-N-oxyamino)benzene derivatives and Mn(II)(hfac)2

✍ Scribed by Katsuya Inoue; Fumiyasu Iwahori; Ashot S Markosyan; Hiizu Iwamura

• Book ID: 104112053
• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 204 KB
• Volume: 198
• Category: Article
• ISSN: 0010-8545
• DOI: 10.1016/s0010-8545(99)00225-8

✦ Synopsis

Bis(hexafluoroacetylacetonato) manganese(II), Mn(hfac) 2 , reacts with the bisnitroxide radicals, 5-R-1,3-bis(N-tert-butyl-N-oxyamino)benzene (1 R ) (R= H, Cl and Br), yielding one-dimensional (1-D) polymeric complexes of formula [Mn(hfac) 2 1 R ] n . X-ray analysis of the complexes has shown that they crystallize in the monoclinic space group P2 1 /n. In this structure, the manganese(II) ions and 1 R molecules make up one-dimensional chains with the bisnitroxide radical serving as a bidentate ligand to Mn(II)(hfac) 2 . The 1 H complex orders antiferromagnetically at 5.5 K, while the 1 Cl and 1 Br complexes show ferrimagnetic order at 4.8 and 5.3 K, respectively. The intrachain exchange interaction parameters for a model of S= 3/2 ferromagnetic chains were found to be, 2J eff /k =239 2 K in all the compounds. J eff is the effective magnetic exchange interaction between units of NO Mn NO. A change in the sign of the interchain exchange interaction is referred to as the change of the shortest exchange path, from the Mn F N(tert-Bu)O (1 Cl and 1 Br ) to N(tert-Bu)O F N(tert-Bu)O (1 H )