| Identifiers | |
|---|---|
| Properties | |
| I5Pa | |
| Molar mass | 865.55823 g·mol−1 |
| Appearance | black needle crystals [1] |
| Related compounds | |
Other anions | Protactinium(V) fluoride Protactinium(V) chloride Protactinium(V) bromide |
Other cations | Praseodymium(III) iodide Thorium(IV) iodide Uranium(IV) iodide |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
Protactinium(V) iodide is an inorganic compound, with the chemical formula of PaI5.
It can be prepared by the reaction of metals protactinium and iodine, or by reacting protactinium(V) chloride, protactinium(V) bromide or protactinium(V) oxide with silicon tetraiodide. [2]
It reacts with antimony trioxide in a vacuum at 150 °C to give the iodide oxides PaOI3 and PaO2I; it reacts with protactinium(V) bromide at 350 °C to obtain mixed halides PaBr3I2. [2] It reacts with the monocarbide at 600 °C to give tetraiodide. [3]
Aristid von Grosse was able to produce pure metallic protactinium with the decomposition of protactinium(V) iodide. [4] [5]
When heated at 300 °C for a long time, it decomposes and iodine is released: [1]
Iodine is a chemical element; it has symbol I and atomic number 53. The heaviest of the stable halogens, it exists at standard conditions as a semi-lustrous, non-metallic solid that melts to form a deep violet liquid at 114 °C (237 °F), and boils to a violet gas at 184 °C (363 °F). The element was discovered by the French chemist Bernard Courtois in 1811 and was named two years later by Joseph Louis Gay-Lussac, after the Ancient Greek Ιώδης 'violet-coloured'.
Protactinium is a chemical element; it has symbol Pa and atomic number 91. It is a dense, radioactive, silvery-gray actinide metal which readily reacts with oxygen, water vapor, and inorganic acids. It forms various chemical compounds, in which protactinium is usually present in the oxidation state +5, but it can also assume +4 and even +3 or +2 states. Concentrations of protactinium in the Earth's crust are typically a few parts per trillion, but may reach up to a few parts per million in some uraninite ore deposits. Because of its scarcity, high radioactivity, and high toxicity, there are currently no uses for protactinium outside scientific research, and for this purpose, protactinium is mostly extracted from spent nuclear fuel.
Titanium tetraiodide is an inorganic compound with the formula TiI4. It is a black volatile solid, first reported by Rudolph Weber in 1863. It is an intermediate in the van Arkel–de Boer process for the purification of titanium.
Tellurium tetraiodide (TeI4) is an inorganic chemical compound. It has a tetrameric structure which is different from the tetrameric solid forms of TeCl4 and TeBr4. In TeI4 the Te atoms are octahedrally coordinated and edges of the octahedra are shared.
Iodine compounds are compounds containing the element iodine. Iodine can form compounds using multiple oxidation states. Iodine is quite reactive, but it is much less reactive than the other halogens. For example, while chlorine gas will halogenate carbon monoxide, nitric oxide, and sulfur dioxide, iodine will not do so. Furthermore, iodination of metals tends to result in lower oxidation states than chlorination or bromination; for example, rhenium metal reacts with chlorine to form rhenium hexachloride, but with bromine it forms only rhenium pentabromide and iodine can achieve only rhenium tetraiodide. By the same token, however, since iodine has the lowest ionisation energy among the halogens and is the most easily oxidised of them, it has a more significant cationic chemistry and its higher oxidation states are rather more stable than those of bromine and chlorine, for example in iodine heptafluoride.
Beryllium iodide is the inorganic compound with the formula BeI2. It is a hygroscopic white solid.
Aristid von Grosse was a German nuclear chemist. During his work with Otto Hahn, he got access to waste material from radium production, and with this starting material he was able in 1927 to isolate protactinium(V) oxide and was later able to produce metallic protactinium by decomposition of protactinium(V) iodide.
Protactinium(V) oxide is a chemical compound with the formula Pa2O5. When it is reduced with hydrogen, it forms PaO2. Aristid V. Grosse was first to prepare 2 mg of Pa2O5 in 1927. Pa2O5 does not dissolve in concentrated HNO3, but dissolves in HF and in a HF + H2SO4 mixture and reacts at high temperatures with solid oxides of alkali metal and alkaline earth metals.
Uranium(IV) iodide, also known as uranium tetraiodide, is an inorganic chemical compound. It is a salt of uranium in oxidation state +4 and iodine.
Germanium(IV) iodide is an inorganic compound with the chemical formula GeI4.
Niobium pentaiodide is the inorganic compound with the formula Nb2I10. Its name comes from the compound's empirical formula, NbI5. It is a diamagnetic, yellow solid that hydrolyses readily. The compound adopts an edge-shared bioctahedral structure, which means that two NbI5 units are joined by a pair of iodide bridges. There is no bond between the Nb centres. Niobium(V) chloride, niobium(V) bromide, tantalum(V) chloride, tantalum(V) bromide, and tantalum(V) iodide, all share this structural motif.
Phosphonium iodide is a chemical compound with the formula PH
4I. It is an example of a salt containing an unsubstituted phosphonium cation. Phosphonium iodide is commonly used as storage for phosphine and as a reagent for substituting phosphorus into organic molecules.
Iron(III) iodide is an inorganic compound with the chemical formula FeI3. It is a thermodynamically unstable compound that is difficult to prepare. Nevertheless, iron(III) iodide has been synthesised in small quantities in the absence of air and water.
Neodymium(II) iodide or neodymium diiodide is an inorganic salt of iodine and neodymium the formula NdI2. Neodymium uses the +2 oxidation state in the compound.
Protactinium(V) bromide is an inorganic compound. It is a halide of protactinium, consisting of protactinium and bromine. It is radioactive and has a chemical formula of PaBr5, which is a red crystal of the monoclinic crystal system.
Europium(III) iodide is an inorganic compound containing europium and iodine with the chemical formula EuI3.
Lutetium compounds are compounds formed by the lanthanide metal lutetium (Lu). In these compounds, lutetium generally exhibits the +3 oxidation state, such as LuCl3, Lu2O3 and Lu2(SO4)3. Aqueous solutions of most lutetium salts are colorless and form white crystalline solids upon drying, with the common exception of the iodide. The soluble salts, such as nitrate, sulfate and acetate form hydrates upon crystallization. The oxide, hydroxide, fluoride, carbonate, phosphate and oxalate are insoluble in water.
Astatine compounds are compounds that contain the element astatine (At). As this element is very radioactive, few compounds have been studied. Less reactive than iodine, astatine is the least reactive of the halogens. Its compounds have been synthesized in nano-scale amounts and studied as intensively as possible before their radioactive disintegration. The reactions involved have been typically tested with dilute solutions of astatine mixed with larger amounts of iodine. Acting as a carrier, the iodine ensures there is sufficient material for laboratory techniques to work. Like iodine, astatine has been shown to adopt odd-numbered oxidation states ranging from −1 to +7.
Protactinium compounds are compounds containing the element protactinium. These compounds usually have protactinium in the +5 oxidation state, although these compounds can also exist in the +2, +3 and +4 oxidation states.
Disulfur diiodide is an unstable inorganic chemical compound with the chemical formula S2I2. Its empirical formula is SI. It is a red-brown solid that decomposes above −30 °C to elemental sulfur and iodine.
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