Interaction of ruthenium(III) chloride with bis(3,5-dimethylpyrazol-1-yl)methane oxyanions, potential κ3-N,N,O scorpionates

When RuCl3 was set to react with both bis(3,5-dimethylpyrazol-1-yl)acetate (bdmpza) and bis(3,5-dimethylpyrazol-1-yl)methane sulfonate (bdmpzsa) new ruthenium(II) complexes were obtained. The reduction of ruthenium(III) was studied by the NMR Evans method and spectrophotometrically, for 1:1 (Ru:L) molar ratios. Using the Evans method pseudo first-order constants of 2.5 × 10−3 s−1 (bdmpzsa) and 3.9 × 10−3 s−1 (bdmpza) were obtained in DMSO-d6 (2% t-butanol) solutions. Spectrophotometrically the corresponding constants were also calculated: 1.1 × 10−3 s−1 for bdmpzsa, and 1.6 × 10−3 s−1, for bdmpza. Both ligands behave as κ3-N,N,O scorpionates but with a weak oxyanionic coordination to the metal, susceptible to be substituted with NEt3 for a 1:1 molar ratio.