High nuclearity cerium-manganese clusters and their structural and magnetic properties: (Ce3Mn7III)-Mn-IV and (Ce5Mn11III)-Mn-IV

作者：Thuijs Annaliese E; Marton Andrea; Stamatatos Theocharis C; Abboud Khalil A; Christou George^*

来源：Polyhedron, 2016, 103: 288-294.

DOI：10.1016/j.poly.2015.03.017

• Manganese
• Lanthanide
• Single-molecule magnet
• Crystal structures
• Cerium

The syntheses, structures, and magnetic properties are reported of two new high nuclearity Ce-Mn oxo carboxylate clusters at high Ce-IV/Mn-III oxidation states and with nuclearities of Ce5Mn11 and Ce3Mn7. The compounds are ((NBU4)-B-n)(2)[Ce5Mn11O13(OH)(2)(O2CPh)(24)(NO3)(2)](NO3) (1) and [Ce3Mn7O8(O2CPh)(17)(H2O)(4)] (2). 1 was prepared from the oxidation of Mn(O2CPh)(2) by ((NBu4)-Bu-n)(2)Ce(NO3)(6), whereas 2 was obtained from the comproportionation reaction of Mn(O2CPh)(2) and (NBu4MnO4)-Bu-n in the presence of Ce(NO3)(3). Both compounds possess unprecedented structures, comprising an irregular metal topology of several edge-fused triangular units with overall virtual C-2 symmetry. Variable-temperature, solid-state dc and ac magnetization studies on 1 and 2 in the 1.8-300 K range revealed predominantly weak antiferromagnetic exchange interactions within the complexes. For 1, the combined dc and ac data indicate an S = 5 ground state but with low-lying excited states consistent with the high nuclearity. For 2, even lower-lying excited states were observed, precluding clear determination of the ground state but with an estimate of S = 2 or 3, or less. Complexes 1 and 2 are new additions to the Ce-Mn family of clusters and the broader class of 3d/4f molecular systems, and 1 is the highest nuclearity Ce-Mn cluster to date.

• 出版日期2016-1-8