Synthesis of homoleptic tetrahedral aryls of rhenium(IV) and ruthenium(IV). X-Ray crystal structures of tetrakis(o-methylphenyl)rhenium(IV), tetrakis(o-methylphenyl)oxorhenium(VI), and tetrakis(o-methylphenyl)-ruthenium(IV)

Abstract

The reaction of ReCl₄(thf)₂(thf = tetrahydrofuran) with o-methylphenylmagnesium bromide leads to the isolation of Re(o-MeC₆H₄)₄, which has been characterised by X-ray crystallography. Air oxidation of this compound allows the isolation of the previously reported paramagnetic ReO(o-MeC₆H₄)₄, which has also been characterised by X-ray crystallography. The interaction of aryl Grignard reagents with NEt₄[RuCl₅(solv)](solv = acetonitrile or tetrahydrofuran) leads to the isolation of homoleptic, tetrahedral ruthenium(IV) species, Ru(aryl)₄, aryl =o-methylphenyl,2,6-dimethylphenyl, and p-t-butylphenyl. Tetrakis(mesityl)ruthenium(IV), mesityl = 2,4,6-trimethylphenyl, and Ru(o-MeC₆H₄)₄ can be obtained from the interaction of diruthenium(II,II) tetra-acetate, Ru₂(µ-O₂CMe)₄, with the respective Grignard reagents. The X-ray crystal structure of Ru(o-MeC₆H₄)₄ has also been determined.