Protactinium tetrafluoride
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| Name = Protactinium tetrafluoride
| ImageFile1 = Kristallstruktur Uran(IV)-fluorid.png
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| CASNo = 61716-26-5
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| StdInChI=1S/4FH.Pa/h4*1H;/q;;;;+4/p-4
| StdInChIKey = CRDGDRUMLTUCQA-UHFFFAOYSA-J
| SMILES = [Pa+4].[F-].[F-].[F-].[F-]
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|Section2={{Chembox Properties
| Pa=1 | F=4
| Appearance = dark brown crystals
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|Section6={{Chembox Related
| OtherCompounds = Uranium tetrafluoride, neptunium tetrafluoride, plutonium tetrafluoride
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Protactinium tetrafluoride is a binary inorganic compound of protactinium metal and fluorine with the chemical formula {{chem2|PaF4}}.{{cite book |last1=Hawkins |first1=Donald T. |title=Binary Fluorides: Free Molecular Structures and Force Fields A Bibliography (1957–1975) |date=6 December 2012 |publisher=Springer Science & Business Media |isbn=978-1-4684-6147-3 |page=50 |url=https://books.google.com/books?id=kOHgBwAAQBAJ&dq=Protactinium+tetrafluoride&pg=PA50 |access-date=2 April 2024 |language=en}}
Synthesis
Protactinium tetrafluoride can be obtained by fluorinating protactinium(IV) oxide with a hydrogen fluoride / hydrogen mixture at 600 °C:
:{{chem2|PaO2 + 4HF -> PaF4 + 2H2O}}
The effect of hydrogen fluoride and hydrogen on protactinium(V) oxide:
:{{chem2|Pa2O5 + 8HF + H2 -> 2PaF4 + 5H2O}}
Physical properties
{{chem2|PaF4}} forms dark brown, monoclinic, needlelike crystals of uranium tetrafluoride structure.{{cite book |title=Advances in Inorganic Chemistry and Radiochemistry |date=28 February 1970 |publisher=Academic Press |isbn=978-0-08-057861-3 |page=7 |url=https://books.google.com/books?id=C7aXnkiqTUcC&dq=Protactinium+tetrafluoride&pg=PA9 |access-date=2 April 2024 |language=en}} The cell parameters are: a = 1.27 nm, b = 1.07 nm, c = 0.842 nm, β = 126.3°.
The compound is soluble in aqueous ammonium fluoride solutions.{{cite book |title=Advances in Inorganic Chemistry and Radiochemistry |date=28 February 1970 |publisher=Academic Press |isbn=978-0-08-057861-3 |page=9 |url=https://books.google.com/books?id=C7aXnkiqTUcC&dq=Protactinium+tetrafluoride&pg=PA9 |access-date=2 April 2024 |language=en}}
Chemical properties
Protactinium tetrafluoride reacts with oxygen and fluorine:{{cite book |title=Proceedings of the Protactinium Chemistry Symposium: Gatlinburg, Tennessee, April 25-26, 1963 : Sessions 1-111 |date=1964 |publisher=United States Atomic Energy Commission, Technical Information Service Extension |page=57 |url=https://books.google.com/books?id=zmdpXPimiOIC&dq=Protactinium+tetrafluoride&pg=PA57 |access-date=2 April 2024 |language=en}}
:{{chem2|2PaF4 + F2 -> 2PaF5}}
:{{chem2|4PaF4 + O2 -> 2Pa2OF8}}
The compound reacts with alkalis:
:{{chem2|PaF4 + 4NaOH -> PaO2 + 4NaF + 2H2O}}
The metal is displaced from the salt by barium:
:{{chem2|PaF4 + 2Ba -> Pa + 2BaF2}}
References
{{Reflist}}
{{Protactinium compounds}}
{{Fluorides}}
{{Actinide halides}}