illustrates the ability of some compounds to be labile (fast reactions) but also stable (high formation constants). The reaction rate is described as follows: rate = k2[M(CN)42−][CN−], where k2 120 M−1−s−1 The bimolecular kinetics implicate a so-called associative pathway. The associative mechanism of exchange entails rate-limiting attack of cyanide on [Pd(CN)4]2−, possibly with the intermediacy of a highly reactive pentacoordinate species [Pd(CN)5]3−. By comparison, the rate constant for [Ni(CN)4]2− is > 500,000 M−1−s−1, whereas [Pt(CN)4]2−exchanges more slowly at 26 M−1s−1. Such associative reactions are characterized by large negative entropies of activation, in this case: -178 and -143 kJ/(mol·K) for Pd and Pt, respectively. Pd(CN)2 has few uses. It has been demonstrated to facilitate the synthesis of alkenyl nitriles from olefins. and as a catalyst in the regioselective reaction between cyanotrimethylsilane and oxiranes. See also Nickel dicyanide References Palladium compounds Cyanides Two-dimensional nanomaterials Coordination polymers