Wu, Q;
Wu, W;
Wu, Y;
Li, W;
Qiao, Y;
Wang, Y;
Wang, B;
(2018)
Controllable synthesis, crystal structure and magnetic properties of Monomer-Dimer Cocrystallized Mn-III Salen-type composite material.
Journal of Molecular Structure
, 1157
pp. 616-620.
10.1016/j.molstruc.2017.12.082.
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Abstract
By the reaction of manganese-Schiff-base complexes with penta-anionic Anderson heteropolyanion, a new supramolecular architecture [Mn2(Salen)2(H2O)2][Mn(Salen)(H2O)2]2Na[IMo6O24]·8H2O (1) (salen = N,N′-ethylene-bis (salicylideneiminate) has been isolated. Compound 1 was characterized by the single-crystal X-ray diffraction, elemental, IR and thermal gravimetric analyses. Structural analysis reveals that the unit cell simultaneously contains MnIII-Salen dimer and monomer cation fragments, for which the Anderson-type polyanions serve as counter anions. In the packing arrangement, all the MnIII dimers are well separated by polyoxometalate units and form tertiary structure together with MnIII monomers. Interestingly, different from the previous work, in the exact same reaction conditions, we are able to template MnIII-Salen complexes into different configurations by varying the charge state of polyanions. Besides, the magnetic properties of 1 were also examined by using both dc and ac magnetic field of the superconducting quantum interference devices. Most importantly, our fitting of the experimental data to a Heisenberg-type spin model shows that there exists a ferromagnetic exchange interaction ∼5 K between the spins (S = 2) on MnIII in the dimer, while antiferromagnetic ones exist among monomers and dimer (∼2 K). This meta-magnetic state could induce a slight spin frustration at low temperature, which would in turn affect the magnetic behavior. In addition, our ac field measurement of the susceptibilities suggests a typical signature for a single-molecule magnet.
| Type: | Article |
|---|---|
| Title: | Controllable synthesis, crystal structure and magnetic properties of Monomer-Dimer Cocrystallized Mn-III Salen-type composite material |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1016/j.molstruc.2017.12.082 |
| Publisher version: | https://doi.org/10.1016/j.molstruc.2017.12.082 |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Schiff-base, Dimer and Monomer, POM, Single molecule magnet, Magnetic analysis |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > MAPS Faculty Office UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > MAPS Faculty Office > Institute for Materials Discovery |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10069187 |
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