MAGNETIC AND SPECTROSCOPIC STUDIES OF MO2X93- ION

Thermal preparations of Cs3Mo2X9 (X = Cl or Br) are reported. The products are isomorphous with their Cr analogs. The unique position of the enneahalodimolybdates is discussed and, as expected, properties intermediate between those of the Cr and W compounds are observed. Thermal stability decreases according to Cr-Cr > Mo-Mo > W-W. Temperatureindependent paramagnetism occurs with Cs3Mo2Cl9, while Cs3Mo2Br9 possesses weak, temperature-dependent paramagnetism The polarized crystal spectrum of Cs3Mo2Cl9 does not clarify the interpretation of the spectra. © 1969, American Chemical Society. All rights reserved.