Hydrothermal Synthesis of Microporous Transition Metal Squarates: Preparation and Structure of [Co_3(mu_3-OH)_2(C_4O_4)_2]-3H_2O

摘要

Many microporous main group oxides have been prepared by hydrothermal synthesis but it has long been a goal to produce lacunary materials with modulated catalytic activity by constructing frameworks with d-block metals in close proximity to the voids.Haushalter et al. have shown how this can be achieved for vanadium and molybdenum phosphates. The usefulness of superheated fluids for preparing extended frameworks based on metal-ligand interactions has recently been demonstrated both by ourselves andothers, and we now wish to report the extension of this technique to the preparation of a cobalt squat ate with a microporous structure. The cobalt-squaric acid system has been extensively investigated under ambient conditions and gives compounds based on the framework found in 1 in most cases; analogous structures are also formed by the corresponding compounds of manganese, iron, nickel, and zinc We report herein on compound 2, which has a structure unlike those previously observed.