Azide-bridged one-dimensional Mn(III) polymers: effects of side group of Schiff base ligands on structure and magnetism.
By changing ancillary tetradentate Schiff base ligands (L), two new one-dimensional azide-bridged manganese(III) coordination complexes [MnIII(L)(mu1,3-N3)]n [L = 5-Fsalen (1), 5-OCH3 (2); salen = N,N'-bis(salicylidene)-1,2-diaminoethane] as well as a mononuclear complex [MnIII(salophen)(N3)] (3) [salophen = N,N'-bis(salicylidene)-o-phenylenediamine] have been successfully obtained. All of them have been structurally and magnetically characterized. In the structures of 1-3 each MnIII ion is in a distorted octahedral geometry with an obvious Jahn-Teller effect, where the tetradentate L ligands all bind in the equatorial mode, whereas in the axial direction, the N3- ion acts as an end-to-end bridge in 1 and 2 while a terminal group in 3 with a methanol molecule at the other end. Magnetic characterization shows that the mu1,3-bridging azide ion proves to mainly transmit antiferromagnetic interaction between MnIII ions, but these three complexes exhibit various magnetic behaviors at low temperatures. Noteworthily, complex 2 behaves as a weak ferromagnet with a relatively large coercive field of 2.3 kOe, much larger than the value reported previously.
Yuan
Mei
M
Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, PR China.
Zhao
Fei
F
Zhang
Wen
W
Wang
Zhe-Ming
ZM
Gao
Song
S