Kinetics of the Oxidative Addition Reaction of Iodine to (Dimethyldithiocarbamato)bis(2,4,6-rimethylphenyl isocyanide)rhodium(I)

Abstract

Abstract The reaction of Rh(dtc)L2 (dtc=S2CN(CH3)2, L=2,4,6-(CH3)3C6H2NC) with an equimolar amount of iodine yields a trans adduct, RhI2(dtc)L2. The rate of this reaction was measured in benzene, employing a stopped flow technique under pseudo-first-order conditions with excess iodine. The result indicates that the reaction proceeds via a charge transfer complex Rh(dtc)L2·I2, which is rearranged in two consecutive zero-order reactions with respect to the I2 concentration; the rearrangement of Rh(dtc)L2·I2 to a cis adduct followed by isomerization to the trans adduct. This mechanism is supported from kinetic data for the reaction of Rh(acac)L2 (acac=CH3COCHCOCH3) with I2. It is also described that RhI(I3)(dtc)L2 and RhI(I3)(acac)L2 were obtained by reactions of Rh(dtc)L2 and Rh(acac)L2 with excess iodine, respectively.