Neptunium bromides

The NIR and IR spectra of both compounds are very similar indicating the same coordination surrounding of neptunyl group. Thermogravimetric analysis counts in the favor of the presence of two crystallization water molecules in the neptunium bromide, so the formula [Np02Br(TPTZ)(H20)] 2H2O was suggested for this compound. 

Manganese trichloride oxide, 4141 Manganese trifluoride, 4335 Mercury(II) bromide, 0269 Mercury(I) fluoride, 4312 Mercury(II) iodide, 4602 Molybdenum hexafluoride, 4365 Molybdenum pentachloride, 4180 Neptunium hexafluoride, 4366 Osmium hexafluoride, 4370 Palladium tetrafluoride, 4347 Palladium trifluoride, 4341... 

Neptunium forms a number of halides in various oxidation states. These include tri-, tetra- and hexafluorides of compositions NpFs, NpF4, and NpFe, respectively trichloride, NpCF and tetrachloride, NpCh tribromide, NpBrs and the triiodide NpN. Neptunium fluorides are formed by heating neptunium dioxide at elevated temperatures with fluorine in the presence of hydrogen fluoride. The tetrachloride, NpCh is obtained similarly by heating the dioxide with carbon tetrachloride vapor at temperatures above 500°C. Neptunium tribromide and triiodide are prepared by heating the dioxide in a sealed vessel at 400°C with aluminum bromide and aluminum iodide, respectively. 

AnBr3 compounds can be prepared by reaction of HBr with the proper actinide hydride, hydroxide, oxalate hex-ahydrate, or oxide. Structures similar to the trichlorides are observed with the structural change from nine coordination to eight coordination occurring with 6-neptunium tribromide. The triiodides to a-americium triiodide have the same eight-coordinate structure found for the heavier bromides and chlorides. From 6-americium triiodide on, the metals are six coordinate. Thl3 is best formulated as Th(IV), 31, and le. ... 

Actinides.— A kinetic study has been made of the reduction of neptunium(vn) and americium(vi) by bromide ion. In both cases two moles of oxidant are consumed in the production of a mole of Brj. The rate law governing the neptunium(vii) reduction is of the form... 

---