Incorporation of tetrahedral Co(II) into a mixed-metal uranyl phosphate framework: synthesis and structure of K2[UO2Co(PO4)2].H2O

The hydrothermal reaction of UO2 with K3[Co(CN)6] and phosphoric acid results in the formation of K2[UO2Co(PO4)2].H2O (KUCoP-1) as blue crystals. The crystal structure of KUCoP-1 was elucidated to reveal a three-dimensional framework constructed from UO7 pentagonal bi-pyramids that edge-share to form dimers that are bridged by phosphate anions into one-dimensional chains that extend down. The phosphate anions also bond to Co2+ creating a tetrahedral environment as well as forming chains that extend along the c axis. The joining of these chains by the phosphate anions yields a three-dimensional framework with channels along the c axis that are occupied by K+ cations and water molecules. (authors)