Direct Determination of the Anisotropy and Exchange Splittings in the Dimeric Single-Molecule Magnet [Mn4O3Cl4(O2CEt)3(py)3]2
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- 作者：Andreas Sieber ; Dolos Foguet-Albiol ; Oliver Waldmann ; Stefan T. Ochsenbein ; Roland Bircher ; George Christou ; Felix Fernandez-Alonso ; Hannu Mutka ; and Hans U. Gü ; del
- 刊名：Inorganic Chemistry
- 出版年：2005
- 出版时间：September 19, 2005
- 年：2005
- 卷：44
- 期：19
- 页码：6771 - 6776
- 全文大小：111K
- 年卷期：v.44,no.19(September 19, 2005)
- ISSN：1520-510X
文摘
Energy splittings resulting from anisotropy and exchange interactions in the dimer of single-molecule magnets[Mn4O3Cl4(O2CEt)3(py)3]2·8MeCN are determined for both an undeuterated and a partially deuterated sample usinginelastic neutron scattering. The antiferromagnetic (AF) exchange coupling between the two Mn4 subunits stronglydepends on their separation. The Cl···Cl distance between the two subunits can be modified either by exchangingthe solvent of crystallization or by deuteration of the C-H···Cl hydrogen bonds. The exchange of acetonitrile forn-hexane leads to a five times greater shortening of the Cl···Cl separation than does full deuteration of all thehydrogen bonds. As a result, the AF exchange coupling constants between the subunits are 0.0073(4) and 0.0103(9) meV in the samples with acetonitrile and n-hexane solvent molecules, respectively, in the crystal structure. Onthe other hand, the effect of C-H···Cl deuteration on the AF exchange coupling is not detectable within theexperimental accuracy of INS.