
TY  - JOUR
A1  - van, Bronswyk W 
A1  - Sheldon, JC 
T1  - Spectroscopic, crystal, and halogen-exchange studies of halogenotrimolybdates(II)
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1967
VL  - 20
IS  - 11
SP  - 2323
EP  - 2329
KW  - 
UR  - https://doi.org/10.1071/CH9672323 
N2  - Quantitative solid (potassium halide disk) and hydrochloric acid solution adsorption spectra of halogenotrimolybdates(II) indicate that the compounds are of a common structural type, both in solid and solution, but that at least two kinds of chloro- or bromo-molybdate(II) are present. Variation of absorption intensities with hydrochloric acid molarity suggests the equilibrium (Mo3Cl12)6-+Cl- &#8596; (Mo3Cl13)7-, and moreover similar intensity changes occur when K6Mo3Cl12 is in KCl.   X-ray diffraction powder photographs of K6Mo3Cl12 and AI7Mo3Cl13,H2O (AI = NH4 or Rb) have been indexed on a pseudo-tetragonal unit cell and indicate 15 and 18 molybdenum atoms per unit oell respectively. The values are decisive for trimers (Mo3) if it is assumed that all the compounds have similar structures.   Halogen-exchange studies support the (Mo3X13)7- parental structure, having four bridging, and nine terminal and labile, halogeno groups, since (NH4)7Mo3Cl13,H2O rapidly exchanges only nine chlorine atoms in 1M hydrochloric acid. 
ER  -

