Abstract: | A new compound of uranium VI has been prepared by thermolysis of uranyl formate diammoniate in an ammonia environment. Chemical analysis and infrared spectrophotometry favor the formula UO3 · HCONH · 0.5H2O. X-Ray analysis is in agreement with an orthorhombic lattice having parameters a = 6.88 Å, b = 23.46 Å, c = 24.67 Å. The photoluminescence spectra of this compound are presented. |