On the exchange of molybdenum by rhenium in γ-Mo4-xRexO11

We present results of X-ray structure refinement of γ-Mo 4-x Re x O 11 for 0 < x < 1 at room temperature. Single crystals of γ-Mo 4-x Re x O 11 have been grown by chemical transport reaction. Space group Pna2 1 has been confirmed, The volume of the unit cell is decreasing with increasing Re content. Re substitutes preferably one out of four Mo sites. We propose that this is accomplished by a mixture of Re 4+ and Re 5+ .