Two uranyl-organic frameworks with formic acid. A novel example of a uranyl-based nanotubular assemblage

Reaction of uranyl nitrate with formic acid in the presence of DABCO or NMe4OH under hydrothermal conditions gave two novel uranyl-organic frameworks. When templated by H-DABCO+ counter-ions, uranyl formate crystallizes as ribbons including μ3-oxo and μ2- and μ3-hydroxo ions. In one experiment with NMe4OH, a nanotubular material was obtained instead of the more usual two- or three-dimensional uranyl formates, with an inner tubule diameter of ca. 6 Å.