Thermodynamics and high-pressure kinetics of a fast carbon dioxide fixation reaction by a (2,6-pyridinedicarboxamidato-hydroxo) nickel(II) complex

The previously reported carbon dioxide fixation reaction by the planar terminal hydroxide complex [Ni(pyN(2)(Me2))(OH)](1-) in DMF has been further characterized by determination of the equilibrium constants K-eq(298) = 2.4 +/- 0.2 x 10(5) M-1 and K-eq(223) = 1.3 +/- 0.1 x 10(7) M-1, as well as the volume of activation for the CO2 binding (Delta V-on(not equal 223) = -21 +/- 3 cm(3) mol(-1)) and back decarboxylation (Delta V-off(not equal 223) = -13 +/- 1 cm(3) mol(-1)) by high-pressure kinetics. The data are consistent with an earlier DFT computation, including the probable nature of the transition state, and support designating the reaction as one of the most completely investigated carbon dioxide fixation reactions of any type.