Influence of a "Dangling" Co(II) Ion Bound to a [MnCo3O4] Oxo Cubane.

摘要: Cobalt(II), in the presence of acetate and nitrate, quantitatively adds to manganese–cobalt oxido cubane MnIVCoIII3O4(OAc)5(py)3 (1) furnish pentametallic dangler complex MnIVCoIII3CoIIO4(OAc)6(NO3)(py)3 (2). Complex 2 is structurally reminiscent photosystem II’s oxygen-evolving center, a rare example transition-metal “dangler” complex. Superconducting quantum interference device magnetometry density functional theory calculations characterize as having an S = 0 ground state arising from antiferromagnetic coupling between CoII MnIV ions. At higher temperatures, uncoupled dominates. The voltammogram has four electrochemical events, two more than that its parent 1, suggesting addition increases available redox states. Structural, electrochemical, magnetic comparisons complexes 1 allow better understanding dangler’s influence on cubane.