Synthesis and crystal structures of (pyH)2[Mo2O4F6] and (pipH2)[Mo2O4F6]; vibrational band assignment for [Mo2O4F6]2- anion

The two closely related compounds (pyH)(2)[Mo2O4F6] and (pipH(2))[Mo2O4F6], (Py = Pyridine, pip = piperazine), were synthesized by the reaction of MoBr3Py3 and [Mo(CO)(5)](2)pip with anhydrous HF in a FEP (fluorinated ethylene propylene) reaction vessel. The presence of traces of water resulted in the formation of oxyfluorides. (pyH)(2)[Mo2O4F6] and (pipH(2))[Mo2O4F6]were characterized by X-ray diffraction and Raman spectroscopy. Geometry of the anion [Mo2O4F6](2-) was optimized using DFT/B3LYP with cc-PVDZ basis set and the interpretation of the measured Raman spectra was offered based on normal modes of calculated spectrum. (C) 2013 Elsevier B.V. All rights reserved.