Probing mechanisms of cobalt-catalyzed dihydrogen production from acidic solutions

Cobalt macrocycles capable of catalyzing the evolution of dihydrogen from acidic acetonitrile solns. are being investigated as part of a collaborative solar energy initiative. These metal complexes mediate electrocatalytic dihydrogen prodn. at relatively pos. potentials (up to -0.26 V vs. SCE). The catalysis is activated by the redn. of Co(II) species to a Co(I) intermediate, which likely adds a proton to give a Co(III) hydride that reacts further to produce dihydrogen. We are employing laser flash-quench methods coupled with time-resolved spectroscopic monitoring to identify key intermediates in the reaction cycle that leads to dihydrogen prodn