X-Ray structural and Raman data, including remarkable resonance Raman effects, for quadruple molybdenum-to-molybdenum bonds

Abstract

The Mo₂(SO₄)₄^4– ion has been studied crystallographically and found to have a very short (2·110 Å) Mo–Mo bond; the Raman spectra of this and other Mo₂⁴⁺ complexes exhibit strong bands (“Mo–Mo stretching”) in the range 345–406 cm^–1 with Mo₂Cl₈^4– compounds showing remarkable resonance Raman enhancements up to the 3rd overtone when irradiated at 4880 Å.