The reduction of (1-(4-cyanophenyl)-3-hydroxy-2-buten-1-one-N)pentaamminecobalt(III) by chromium(II)

Abstract

The reduction of the title compound,[Formula: see text]by chromium(II) is first order in Cr(II) and obeys the rate law kobsd = k1Ka′/(Ka′ + [H+]) at 25.0 °C and I = 1.0 mol L−1 (LiClO4) with k1 = (2.9 ± 0.1) × 104 L mol−1 s−1 and Ka′ = 0.86 ± 0.03 mol L−1. In the rate law, k1 refers to reduction of the 3+ ion above and the Ka′ is the acid dissociation constant for the protonated form of 1. The reduction occurs by a remote attack inner-sphere mechanism with complete transfer of the organic ligand to chromium.