Nitromethane as a ligand. Part I: Complexes with some divalent metals and the hexachloroantimonate anion

A series of new complexes is reported with nitromethane as a ligand: viz. [M(CH3NO2)6]2+[SbCl6]2− where M is Mg(II), Ca(II), Sr(II), Mn(II), Fe(II), Co(II), Ni(II), and Zn(II). The compounds have been identified by chemical analysis and with the aid of physical measurements. No shift in the N → O stretching frequencies has been observed. The NO2 rocking mode (B1) shifts to higher frequencies. Ligand field spectra for the Co(II) and Ni(II) compounds are investigated. Values for Dq and B are reported and the ligand is placed in the spectrochemical and nephelauxetic series. It is concluded that complexes of nitromethane can serve as precursors of coordination compounds of other weakly nucleophilic ligands.