Flexibility of Paramagnetic (d~1) Organometallic Dithiolene Complexes Cp_2M(dmit)r (M = Mo, W) Studied by Raman Spectroscopy

摘要

The radical cation salts of the Cp_2M(dmit) complexes (where M = Mo, W; dmit~(2-) =1,3-dithiole-2-thione-4,5-dithiolate; Cp=cyclopentadienyl) have been obtained and structurally characterized with a variety of anions such as Br~-, BF_4~-, PF_6~-, AsF_6~-, SbF_6~-, TCNQF_4~-, ReO(dmit)_2~- [1-4]. From the crystallographic investigations it was shown that the folding angle of the d~1 [Cp_2M(dmit)]~+ (M = Mo, W) cations is strongly dependent on the counter ion and the crystal structure. The complex folding allows a mixing of π orbital of the dmit ligand with the d orbital of Cp_2Mo or Cp_2W and is associated with a shift of charge density, what has an influence on their vibrational spectra. In this work, we show that vibrational spectroscopy can be applied for investigation of complex deformations in the solid state. A correlation between the folding angle and the Raman spectroscopic properties can be used to unravel the eventual metallacycle distortions when structural data are unavailable.