Cyclam basicity effects

The basic reaction catalyzed by CODH is related to the water gas shift reaction employed industrially to generate H2 by the reaction of CO and H2O. Industrially the process is iron-catalyzed, and numerous organometallic complexes effect the same reaction [133]. Additionally, square-planar Ni(II) complexes electrocatalyze the reduction of CO2 to CO, including [Ni (cyclam)] (cyclam = 1,4,8,11-tetraazacyclotetradecane), nickel-porphyrins and phthalocyanines. The cluster [Fe4S4(SR)4] and certain Fe-porphyrins also catalyze this reaction [124]. 

The discussion commences with examples illustrating the effectiveness of the first synthetic approach, where the manifestation of the coordination template effect of the metal template is evident. Thus, for instance, interaction of [M(en)2] " , where M = Ni, Cu or Pd, with an excess of formaldehyde and carbon acid nitroethane in basic solution gives the cyclam-substituted derivatives [M(L130)] " in high yield (Eq. 2.73) [160-162]. 

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