An Extremely Porous Hydrogen-Bonded Framework Composed of d-Penicillaminato (Co2Au3I)-Au-III Complex Anions and Aqua Cobalt(II) Cations: Formation and Stepwise Structural Transformation

摘要

A unique example of a hydrogen-bonded ionic solid with a porosity of 80%, [Co(H2O)(6)](3)[Co2Au3(d-pen-N,S)(6)](2) (1; d-H(2)pen=d-penicillamine), composed of [Co(H2O)(6)](2+) cations and [Co2Au3(d-pen-N,S)(6)](3-) anions, is reported. Solid 1 was kinetically produced and was then transformed stepwise into two more thermodynamically stable solids with lower porosities, [Co(H2O)(4)][Co(H2O)(6)](2)[Co2Au3(d-pen-N,S)(6)](2) (2) and [Co(H2O)(4)](3)[Co2Au3(d-pen-N,S)(6)](2) (3), through the coordination of the free carboxylate groups in [Co2Au3(d-pen-N,S)(6)](3-) to Co-II centers. Solids 1-3 were structurally characterized, and the selective adsorption of small molecules into their pores was investigated.