Synthesis and characterization of Cs2Mo6X14 (X= br or 1) hexamolybdenum cluster halides: Efficient Mo-6 cluster precursors for solution chemistry syntheses

Cs2Mo6Br14 (1) and Cs2Mo6I14 (2) have been synthesized by solid state chemistry techniques and structurally characterized by single crystal X-ray diffraction. They crystallize in the P (3) over bar 1c space group (Nr. 163) with the following lattice parameters: a = 10.1925(1) Angstrom, c = 15.0690(3) Angstrom, Z = 2 for 1; a = 10.804(5) Angstrom, c = 16.258(5) A, Z = 2 for 2. These clusters halides, whose structures are related to that of Cs2Mo6Cl8Br6, are built up from discrete [(Mo6X8i)X-6(a)](2-) anionic units (X - Br, 1) stacked according to an hexagonal close-packing arrangement. In the present work, the influence of the halogen on the cesium sites will be evidenced and discussed. Furthermore, a simple high yield preparation method of (TBA)(2)(Mo6X8X6a)-X-i will be proposed starting from (Cs2MoX14)-X-6.