Synthesis, crystal structure and magnetic properties of Li2InMo3O8: A novel reduced molybdenum oxide containing magnetic Mo3 clusters

• The new quaternary reduced molybdenum oxide containing Mo3 clusters, Li2InMo3O8, was synthesized by solid state reaction.
• Single-crystal X-ray study.
• One unpaired electron per Mo3 cluster leading to a paramagnetic spin behavior with an effective magnetic moment of 1.5 μB per Mo3 cluster.
• Magnetic susceptibility measurements show a maximum at 25 K arising probably from an antiferromagnetic ordering between the Mo3 clusters.

Powder samples and single crystals of Li2InMo3O8 were obtained by solid state reaction. The structure was determined by single-crystal X-ray diffraction (771 independent reflections for 33 refinable, R1=0.0158 and wR2=0.0354). Li2InMo3O8 is isomorphous with Li2SnMo3O8 and crystallizes in the hexagonal space group P63mc with unit-cell parameters a=5.7931(2) Å, c=10.4681(4) Å and Z=2. The crystal structure consists of distorted hexagonal-close-packed oxygen layers with stacking sequence abac along [0 0 1] and that are held together by alternating lithium–indium and molybdenum layers. The Li+ and In3+ ions occupy, respectively, tetrahedral and octahedral sites in the ratio 2:1. The Mo atoms occupy octahedral sites and form strongly bonded triangular clusters involving three MoO6 octahedra that are each shared along two edges, constituting a Mo3O13 unit. The variations of the Mo–Mo and Mo–O bond lengths according to the number of electrons per Mo3 cluster are discussed. The trivalent oxidation state of the indium leads to one unpaired electron per Mo3 and thus gives rise to a paramagnetic spin behavior with an effective magnetic moment of 1.5 μB per Mo3 cluster. The magnetic susceptibility vs. temperature curve also shows a maximum at 25 K arising probably from an antiferromagnetic ordering between the Mo3 clusters.

We present here the synthesis, the crystal structure, and the magnetic properties of the new quaternary compound Li2InMo3O8 containing magnetic Mo3O13 units with one unpaired electron.Figure optionsDownload as PowerPoint slide